Iron-deficiency anemia is a common, easily treated condition that occurs if you don't have enough iron in your body. Low iron levels usually are due to blood loss, poor diet, or an inability to absorb enough iron from food.
Iron-deficiency anemia is a common type of anemia. The term "anemia" usually refers to a condition in which your blood has a lower than normal number of red blood cells. Red blood cells carry oxygen and remove carbon dioxide (a waste product) from your body.
Anemia also can occur if your red blood cells don't contain enough hemoglobin (HEE-muh-glow-bin). Hemoglobin is an iron-rich protein that carries oxygen from the lungs to the rest of the body.
Iron-deficiency anemia usually develops over time if your body doesn't have enough iron to build healthy red blood cells. Without enough iron, your body starts using the iron it has stored. Soon, the stored iron gets used up.
After the stored iron is gone, your body makes fewer red blood cells. The red blood cells it does make have less hemoglobin than normal.
Iron-deficiency anemia can cause fatigue (tiredness), shortness of breath, chest pain, and other symptoms. Severe iron-deficiency anemia can lead to heart problems, infections, problems with growth and development in children, and other complications.
Infants and young children and women are the two groups at highest risk for iron-deficiency anemia.
Doctors usually can successfully treat iron-deficiency anemia. Treatment will depend on the cause and severity of the condition. Treatments may include dietary changes, medicines, and surgery.
Severe iron-deficiency anemia may require treatment in a hospital, blood transfusions, iron injections, or intravenous iron therapy.
Not having enough iron in your body causes iron-deficiency anemia. Lack of iron usually is due to blood loss, poor diet, or an inability to absorb enough iron from food.
When you lose blood, you lose iron. If you don't have enough iron stored in your body to make up for the lost iron, you'll develop iron-deficiency anemia.
In women, long or heavy menstrual periods or bleeding fibroids in the uterus may cause low iron levels. Blood loss that occurs during childbirth is another cause of low iron levels in women.
Internal bleeding (bleeding inside the body) also may lead to iron-deficiency anemia. This type of blood loss isn't always obvious, and it may occur slowly. Some causes of internal bleeding are:
Blood loss from severe injuries, surgery, or frequent blood drawings also can cause iron-deficiency anemia.
The best sources of iron are meat, poultry, fish, and iron-fortified foods (foods that have iron added). If you don't eat these foods regularly, or if you don't take an iron supplement, you're more likely to develop iron-deficiency anemia.
Vegetarian diets can provide enough iron if you eat the right foods. For example, good nonmeat sources of iron include iron-fortified breads and cereals, beans, tofu, dried fruits, and spinach and other dark green leafy vegetables.
During some stages of life, such as pregnancy and childhood, it may be hard to get enough iron in your diet. This is because your need for iron increases during these times of growth and development.
Even if you have enough iron in your diet, your body may not be able to absorb it. This can happen if you have intestinal surgery (such as gastric bypass) or a disease of the intestine (such as Crohn's disease or celiac disease).
Prescription medicines that reduce acid in the stomach also can interfere with iron absorption.
Infants and young children need a lot of iron to grow and develop. The iron that full-term infants have stored in their bodies is used up in the first 4 to 6 months of life.
Premature and low-birth-weight babies (weighing less than 5.5 pounds) are at even greater risk for iron-deficiency anemia. These babies don't have as much iron stored in their bodies as larger, full-term infants.
Iron-fortified baby food or iron supplements, when used properly, can help prevent iron-deficiency anemia in infants and young children. Talk with your child's doctor about your child's diet.
Young children who drink a lot of cow's milk may be at risk for iron-deficiency anemia. Milk is low in iron, and too much milk may take the place of iron-rich foods in the diet. Too much milk also may prevent children's bodies from absorbing iron from other foods.
Children who have lead in their blood also may be at risk for iron-deficiency anemia. Lead can interfere with the body's ability to make hemoglobin. Lead may get into the body from breathing in lead dust, eating lead in paint or soil, or drinking water that contains lead.
Teens are at risk for iron-deficiency anemia if they're underweight or have chronic (ongoing) illnesses. Teenage girls who have heavy periods also are at increased risk for the condition.
Women of childbearing age are at higher risk for iron-deficiency anemia because of blood loss during their monthly periods. About 1 in 5 women of childbearing age has iron-deficiency anemia.
Pregnant women also are at higher risk for the condition because they need twice as much iron as usual. The extra iron is needed for increased blood volume and for the fetus' growth.
About half of all pregnant women develop iron-deficiency anemia. The condition can increase a pregnant woman's risk for a premature or low-birth-weight baby.
Adults who have internal bleeding, such as intestinal bleeding, can develop iron-deficiency anemia due to blood loss. Certain conditions, such as colon cancer and bleeding ulcers, can cause blood loss. Some medicines, such as aspirin, also can cause internal bleeding.
People who get kidney dialysis treatment may develop iron-deficiency anemia. This is because blood is lost during dialysis. Also, the kidneys are no longer able to make enough of a hormone that the body needs to produce red blood cells.
People who have gastric bypass surgery also may develop iron-deficiency anemia. This type of surgery can prevent the body from absorbing enough iron.
Certain eating patterns or habits may put you at higher risk for iron-deficiency anemia. This can happen if you:
he signs and symptoms of iron-deficiency anemia depend on its severity. Mild to moderate iron-deficiency anemia may have no signs or symptoms.
When signs and symptoms do occur, they can range from mild to severe. Many of the signs and symptoms of iron-deficiency anemia apply to all types of anemia.
The most common symptom of all types of anemia is fatigue (tiredness). Fatigue occurs because your body doesn't have enough red blood cells to carry oxygen to its many parts.
Also, the red blood cells your body makes have less hemoglobin than normal. Hemoglobin is an iron-rich protein in red blood cells. It helps red blood cells carry oxygen from the lungs to the rest of the body.
Anemia also can cause shortness of breath, dizziness, headache, coldness in your hands and feet, pale skin, chest pain, weakness, and fatigue (tiredness).
If you don't have enough hemoglobin-carrying red blood cells, your heart has to work harder to move oxygen-rich blood through your body. This can lead to irregular heartbeats called arrhythmias (ah-RITH-me-ahs), a heart murmur, an enlarged heart, or even heart failure.
In infants and young children, signs of anemia include poor appetite, slowed growth and development, and behavioral problems.
Signs and symptoms of iron deficiency may include brittle nails, swelling or soreness of the tongue, cracks in the sides of the mouth, an enlarged spleen, and frequent infections.
People who have iron-deficiency anemia may have an unusual craving for nonfood items, such as ice, dirt, paint, or starch. This craving is called pica (PI-ka or PE-ka).
Some people who have iron-deficiency anemia develop restless legs syndrome (RLS). RLS is a disorder that causes a strong urge to move the legs. This urge to move often occurs with strange and unpleasant feelings in the legs. People who have RLS often have a hard time sleeping.
Iron-deficiency anemia can put children at greater risk for lead poisoning and infections.
Some signs and symptoms of iron-deficiency anemia are related to the condition's causes. For example, a sign of intestinal bleeding is bright red blood in the stools or black, tarry-looking stools.
Very heavy menstrual bleeding, long periods, or other vaginal bleeding may suggest that a woman is at risk for iron-deficiency anemia.
Your doctor will diagnose iron-deficiency anemia based on your medical history, a physical exam, and the results from tests and procedures.
Once your doctor knows the cause and severity of the condition, he or she can create a treatment plan for you.
Mild to moderate iron-deficiency anemia may have no signs or symptoms. Thus, you may not know you have it unless your doctor discovers it from a screening test or while checking for other problems.
Primary care doctors often diagnose and treat iron-deficiency anemia. These doctors include pediatricians, family doctors, gynecologists/obstetricians, and internal medicine specialists.
A hematologist (a blood disease specialist), a gastroenterologist (a digestive system specialist), and other specialists also may help treat iron-deficiency anemia.
Your doctor will ask about your signs and symptoms and any past problems you've had with anemia or low iron. He or she also may ask about your diet and whether you're taking any medicines.
If you're a woman, your doctor may ask whether you might be pregnant.
Your doctor will do a physical exam to look for signs of iron-deficiency anemia. He or she may:
Many tests and procedures are used to diagnose iron-deficiency anemia. They can help confirm a diagnosis, look for a cause, and find out how severe the condition is.
Often, the first test used to diagnose anemia is a complete blood count (CBC). The CBC measures many parts of your blood.
This test checks your hemoglobin and hematocrit (hee-MAT-oh-crit) levels. Hemoglobin is an iron-rich protein in red blood cells that carries oxygen to the body. Hematocrit is a measure of how much space red blood cells take up in your blood. A low level of hemoglobin or hematocrit is a sign of anemia.
The normal range of these levels varies in certain racial and ethnic populations. Your doctor can explain your test results to you.
The CBC also checks the number of red blood cells, white blood cells, and platelets in your blood. Abnormal results may be a sign of infection, a blood disorder, or another condition.
Finally, the CBC looks at mean corpuscular (kor-PUS-kyu-lar) volume (MCV). MCV is a measure of the average size of your red blood cells. The results may be a clue as to the cause of your anemia. In iron-deficiency anemia, for example, red blood cells usually are smaller than normal.
If the CBC results confirm you have anemia, you may need other blood tests to find out what's causing the condition, how severe it is, and the best way to treat it.
Reticulocyte count. This test measures the number of reticulocytes (re-TIK-u-lo-sites) in your blood. Reticulocytes are young, immature red blood cells. Over time, reticulocytes become mature red blood cells that carry oxygen throughout your body.
A reticulocyte count shows whether your bone marrow is making red blood cells at the correct rate.
Peripheral smear. For this test, a sample of your blood is examined under a microscope. If you have iron-deficiency anemia, your red blood cells will look smaller and paler than normal.
Tests to measure iron levels. These tests can show how much iron has been used from your body's stored iron. Tests to measure iron levels include:
Other tests. Your doctor also may recommend tests to check your hormone levels, especially your thyroid hormone. You also may have a blood test for a chemical called erythrocyte protoporphyrin. This chemical is a building block for hemoglobin.
Children also may be tested for the level of lead in their blood. Lead can make it hard for the body to produce hemoglobin.
To check whether internal bleeding is causing your iron-deficiency anemia, your doctor may suggest a fecal occult blood test. This test looks for blood in the stools and can detect bleeding in the intestines.
If the test finds blood, you may have other tests and procedures to find the exact spot of the bleeding. These tests and procedures may look for bleeding in the stomach, upper intestines, colon, or pelvic organs.
Treatment for iron-deficiency anemia will depend on its cause and severity. Treatments may include dietary changes and supplements, medicines, and surgery.
Severe iron-deficiency anemia may require a blood transfusion, iron injections, or intravenous (IV) iron therapy. Treatment may need to be done in a hospital.
The goals of treating iron-deficiency anemia are to treat its underlying cause and restore normal levels of red blood cells, hemoglobin, and iron.
You may need iron supplements to build up your iron levels as quickly as possible. Iron supplements can correct low iron levels within months. Supplements come in pill form or in drops for children.
Large amounts of iron can be harmful, so take iron supplements only as your doctor prescribes. Keep iron supplements out of reach from children. This will prevent them from taking an overdose of iron.
Iron supplements can cause side effects, such as dark stools, stomach irritation, and heartburn. Iron also can cause constipation, so your doctor may suggest that you use a stool softener.
Your doctor may advise you to eat more foods that are rich in iron. The best source of iron is red meat, especially beef and liver. Chicken, turkey, pork, fish, and shellfish also are good sources of iron.
The body tends to absorb iron from meat better than iron from nonmeat foods. However, some nonmeat foods also can help you raise your iron levels. Examples of nonmeat foods that are good sources of iron include:
The Nutrition Facts labels on packaged foods will show how much iron the items contain. The amount is given as a percentage of the total amount of iron you need every day.
Vitamin C helps the body absorb iron. Good sources of vitamin C are vegetables and fruits, especially citrus fruits. Citrus fruits include oranges, grapefruits, tangerines, and similar fruits. Fresh and frozen fruits, vegetables, and juices usually have more vitamin C than canned ones.
If you're taking medicines, ask your doctor or pharmacist whether you can eat grapefruit or drink grapefruit juice. Grapefruit can affect the strength of a few medicines and how well they work.
Other fruits rich in vitamin C include kiwi fruit, strawberries, and cantaloupes.
Vegetables rich in vitamin C include broccoli, peppers, Brussels sprouts, tomatoes, cabbage, potatoes, and leafy green vegetables like turnip greens and spinach.
If blood loss is causing iron-deficiency anemia, treatment will depend on the cause of the bleeding. For example, if you have a bleeding ulcer, your doctor may prescribe antibiotics and other medicines to treat the ulcer.
If a polyp or cancerous tumor in your intestine is causing bleeding, you may need surgery to remove the growth.
If you have heavy menstrual flow, your doctor may prescribe birth control pills to help reduce your monthly blood flow. In some cases, surgery may be advised.
If your iron-deficiency anemia is severe, you may get a transfusion of red blood cells. A blood transfusion is a safe, common procedure in which blood is given to you through an IV line in one of your blood vessels. A transfusion requires careful matching of donated blood with the recipient's blood.
A transfusion of red blood cells will treat your anemia right away. The red blood cells also give a source of iron that your body can reuse. However, a blood transfusion is only a short-term treatment. Your doctor will need to find and treat the cause of your anemia.
Blood transfusions are usually reserved for people whose anemia puts them at a higher risk for heart problems or other severe health issues.
For more information, go to the Health Topics Blood Transfusion article.
If you have severe anemia, your doctor may recommend iron therapy. For this treatment, iron is injected into a muscle or an IV line in one of your blood vessels.
IV iron therapy presents some safety concerns. It must be done in a hospital or clinic by experienced staff. Iron therapy usually is given to people who need iron long-term but can't take iron supplements by mouth. This therapy also is given to people who need immediate treatment for iron-deficiency anemia.
Eating a well-balanced diet that includes iron-rich foods may help you prevent iron-deficiency anemia.
Taking iron supplements also may lower your risk for the condition if you're not able to get enough iron from food. Large amounts of iron can be harmful, so take iron supplements only as your doctor prescribes.
For more information about diet and supplements, go to "How Is Iron-Deficiency Anemia Treated?"
Infants and young children and women are the two groups at highest risk for iron-deficiency anemia. Special measures can help prevent the condition in these groups.
A baby's diet can affect his or her risk for iron-deficiency anemia. For example, cow's milk is low in iron. For this and other reasons, cow's milk isn't recommended for babies in their first year. After the first year, you may need to limit the amount of cow's milk your baby drinks.
Also, babies need more iron as they grow and begin to eat solid foods. Talk with your child's doctor about a healthy diet and food choices that will help your child get enough iron.
Your child's doctor may recommend iron drops. However, giving a child too much iron can be harmful. Follow the doctor's instructions and keep iron supplements and vitamins away from children. Asking for child-proof packages for supplements can help prevent overdosing in children.
Because recent research supports concerns that iron deficiency during infancy and childhood can have long-lasting, negative effects on brain health, the American Academy of Pediatrics recommends testing all infants for anemia at 1 year of age.
Women of childbearing age may be tested for iron-deficiency anemia, especially if they have:
The Centers for Disease Control and Prevention (CDC) has developed guidelines for who should be screened for iron deficiency, and how often:
For pregnant women, medical care during pregnancy usually includes screening for anemia. Also, your doctor may prescribe iron supplements or advise you to eat more iron-rich foods. This not only will help you avoid iron-deficiency anemia, but also may lower your risk of having a low-birth-weight baby.
If you have iron-deficiency anemia, get ongoing care to make sure your iron levels are improving. At your checkups, your doctor may change your medicines or supplements. He or she also may suggest ways to improve your diet.
Take iron supplements only with your doctor's approval, and only as he or she prescribes. It's possible to have too much iron in your body (a condition called iron overload). Too much iron in your body can damage your organs.
You may have fatigue (tiredness) and other symptoms of iron-deficiency anemia until your iron levels return to normal, which can take months. Tell your doctor if you have any new symptoms or if your symptoms get worse.
The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.
Researchers have learned a lot about anemia and other blood diseases and conditions over the years. That knowledge has led to advances in medical care.
Many questions remain about blood diseases and conditions, including iron-deficiency anemia. The NHLBI continues to support research aimed at learning more about these illnesses.
For example, NHLBI-supported research on iron-deficiency anemia includes studies that explore:
Much of this research depends on the willingness of volunteers to take part in clinical trials.
Clinical trials test new ways to prevent, diagnose, or treat various diseases and conditions. For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.
By taking part in a clinical trial, you can gain access to new treatments before they're widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don't directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.
If you volunteer for a clinical trial, the research will be explained to you in detail. You'll learn about treatments and tests you may receive, and the benefits and risks they may pose. You'll also be given a chance to ask questions about the research. This process is called informed consent.
If you agree to take part in the trial, you'll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.
For more information about clinical trials related to iron-deficiency anemia, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:
For more information about clinical trials for children, visit the NHLBI's Children and Clinical Studies Web page.
Source: NHLBI, NIH
Hemolytic anemia (HEE-moh-lit-ick uh-NEE-me-uh) is a condition in which red blood cells are destroyed and removed from the bloodstream before their normal lifespan is over.
Red blood cells are disc-shaped and look like doughnuts without holes in the center. These cells carry oxygen to your body. They also remove carbon dioxide (a waste product) from your body.
Red blood cells are made in the bone marrow—a sponge-like tissue inside the bones. They live for about 120 days in the bloodstream and then die.
White blood cells and platelets (PLATE-lets) also are made in the bone marrow. White blood cells help fight infections. Platelets stick together to seal small cuts or breaks on blood vessel walls and stop bleeding.
When blood cells die, the body's bone marrow makes more blood cells to replace them. However, in hemolytic anemia, the bone marrow can't make red blood cells fast enough to meet the body's needs.
Hemolytic anemia can lead to many health problems, such as fatigue (tiredness), pain, irregular heartbeats called arrhythmias (ah-RITH-me-ahs), an enlarged heart, and heart failure.
Hemolytic anemia is a type of anemia. The term "anemia" usually refers to a condition in which the blood has a lower than normal number of red blood cells.
Anemia also can occur if your red blood cells don't contain enough hemoglobin (HEE-muh-glow-bin). Hemoglobin is an iron-rich protein that carries oxygen from the lungs to the rest of the body.
Anemia has three main causes: blood loss, lack of red blood cell production, or high rates of red blood cell destruction.
Hemolytic anemia is caused by high rates of red blood cell destruction. Many diseases, conditions, and factors can cause the body to destroy its red blood cells.
These causes can be inherited or acquired. "Inherited" means your parents passed the gene(s) for the condition on to you. "Acquired" means you aren't born with the condition, but you develop it. Sometimes the cause of hemolytic anemia isn't known.
There are many types of hemolytic anemia. Treatment and outlook depend on what type you have and how severe it is. The condition can develop suddenly or slowly. Symptoms can range from mild to severe.
Hemolytic anemia often can be successfully treated or controlled. Mild hemolytic anemia may need no treatment at all. Severe hemolytic anemia requires prompt and proper treatment, or it may be fatal.
Inherited forms of hemolytic anemia are lifelong conditions that may require ongoing treatment. Acquired forms of hemolytic anemia may go away if the cause of the condition is found and corrected.
There are many types of hemolytic anemia. The condition can be inherited or acquired. "Inherited" means your parents passed the gene for the condition on to you. "Acquired" means you aren't born with the condition, but you develop it.
With inherited hemolytic anemias, one or more of the genes that control red blood cell production are faulty. This can lead to problems with the hemoglobin, cell membrane, or enzymes that maintain healthy red blood cells.
The abnormal cells may be fragile and break down while moving through the bloodstream. If this happens, an organ called the spleen may remove the cell debris from the bloodstream.
Sickle cell anemia is a serious, inherited disease. In this disease, the body makes abnormal hemoglobin. This causes the red blood cells to have a sickle, or crescent, shape.
Sickle cells don't last as long as healthy red blood cells. They usually die after only about 10 to 20 days. The bone marrow can't make new red blood cells fast enough to replace the dying ones.
In the United States, sickle cell anemia mainly affects African Americans.
Thalassemias (thal-a-SE-me-ahs) are inherited blood disorders in which the body doesn't make enough of certain types of hemoglobin. This causes the body to make fewer healthy red blood cells than normal.
Thalassemias most often affect people of Southeast Asian, Indian, Chinese, Filipino, Mediterranean, or African origin or descent.
In this condition, a defect in the surface membrane (the outer covering) of red blood cells causes them to have a sphere, or ball-like, shape. These blood cells have a lifespan that's shorter than normal.
Hereditary spherocytosis (SFER-o-si-to-sis) is the most common cause of hemolytic anemia among people of Northern European descent.
Like hereditary spherocytosis, this condition also involves a problem with the cell membrane. In this condition, the red blood cells are elliptic (oval) in shape. They aren't as flexible as normal red blood cells, and they have a shorter lifespan.
In G6PD deficiency, the red blood cells are missing an important enzyme called G6PD. G6PD is part of the normal chemistry inside red blood cells.
In G6PD deficiency, if red blood cells come into contact with certain substances in the bloodstream, the missing enzyme causes the cells to rupture (burst) and die.
Many factors can trigger the breakdown of the red blood cells. Examples include taking sulfa or antimalarial medicines; being exposed to naphthalene, a substance found in some moth balls; eating fava beans; or having an infection.
G6PD deficiency mostly affects males of African or Mediterranean descent. In the United States, the condition is more common among African Americans than Caucasians.
In this condition, the body is missing an enzyme called pyruvate (PI-ru-vate) kinase. Not having enough of this enzyme causes red blood cells to break down easily.
This disorder is more common among the Amish than other groups.
With acquired hemolytic anemias, your red blood cells may be normal. However, some other disease or factor causes the body to destroy red blood cells and remove them from the bloodstream.
The destruction of the red blood cells occurs in the bloodstream or, more commonly, in the spleen.
In immune hemolytic anemia, your immune system destroys your red blood cells. The three main types of immune hemolytic anemia are autoimmune, alloimmune, and drug-induced.
Autoimmune hemolytic anemia (AIHA). In this condition, your immune system makes antibodies (proteins) that attack your red blood cells. Why this happens isn't known.
AIHA accounts for half of all cases of hemolytic anemia. AIHA may come on very quickly and become serious.
Having certain diseases or infections can raise your risk for AIHA. Examples include:
AIHA also can develop after you have a blood and marrow stem cell transplant.
In some types of AIHA, the antibodies made by the body are called warm antibodies. This means they're active (that is, they destroy red blood cells) at warm temperatures, such as body temperature.
In other types of AIHA, the body makes cold-reactive antibodies. These antibodies are active at cold temperatures.
Cold-reactive antibodies can become active when parts of the body, such as the hands or feet, are exposed to temperatures lower than 32 to 50 degrees Fahrenheit (0 to 10 degrees Celsius).
Warm antibody AIHA is more common than cold antibody AIHA.
Alloimmune hemolytic anemia. This type of hemolytic anemia occurs if your body makes antibodies against red blood cells that you get from a blood transfusion. This can happen if the transfused blood is a different blood type than your blood.
This type of hemolytic anemia also can occur during pregnancy if a woman has
Rh-negative blood and her baby has Rh-positive blood. "Rh-negative" and "Rh-positive" refer to whether your blood has Rh factor. Rh factor is a protein on red blood cells.
For more information, go to the Health Topic Rh Incompatibility article.
Drug-induced hemolytic anemia. Certain medicines can cause a reaction that develops into hemolytic anemia. Some medicines, such as penicillin, bind to red blood cell surfaces and can cause antibodies to develop.
Other medicines cause hemolytic anemia in other ways. Examples of these medicines include chemotherapy, acetaminophen, quinine and antimalarial medicines, anti-inflammatory medicines, and levodopa.
Physical damage to red blood cell membranes can cause them to break down faster than normal. Damage may be due to:
Blood cell damage also may occur in the limbs as a result of doing strenuous activities, such as taking part in marathons.
Paroxysmal nocturnal hemoglobinuria (HE-mo-GLO-bih-NYU-re-ah), or PNH, is a disorder in which the red blood cells are faulty due to a lack of certain proteins. The body destroys these cells more quickly than normal.
People who have PNH are at increased risk for blood clots in the veins and low levels of white blood cells and platelets.
Certain infections and substances also can damage red blood cells and lead to hemolytic anemia. Examples include malaria and blackwater fever, tick-borne diseases, snake venom, and toxic chemicals.
The immediate cause of hemolytic anemia is the early destruction of red blood cells. This means that red blood cells are destroyed and removed from the bloodstream before their normal lifespan is over.
Many diseases, conditions, and factors can cause the body to destroy its red blood cells. These causes can be inherited or acquired. "Inherited" means your parents passed the gene for the condition on to you. "Acquired" means you aren't born with the condition, but you develop it.
Sometimes, the cause of hemolytic anemia isn't known.
For more information about the specific causes of hemolytic anemia, go to "Types of Hemolytic Anemia."
In inherited hemolytic anemias, the genes that control how red blood cells are made are faulty. You can get a faulty red blood cell gene from one or both of your parents.
Different types of faulty genes cause different types of inherited hemolytic anemia. However, in each type, the body makes abnormal red blood cells. The problem with the red blood cells may involve the hemoglobin, cell membrane, or enzymes that maintain healthy red blood cells.
The abnormal cells may be fragile and break down while moving through the bloodstream. If this happens, an organ called the spleen may remove the cell debris from the bloodstream.
In acquired hemolytic anemias, the body makes normal red blood cells. However, a disease, condition, or other factor destroys the cells. Examples of conditions that can destroy the red blood cells include:
Hemolytic anemia can affect people of all ages and races and both sexes. Some types of hemolytic anemia are more likely to occur in certain populations than others.
For example, glucose-6-phosphate dehydrogenase (G6PD) deficiency mostly affects males of African or Mediterranean descent. In the United States, the condition is more common among African Americans than Caucasians.
In the United States, sickle cell anemia mainly affects African Americans.
The signs and symptoms of hemolytic anemia will depend on the type and severity of the disease.
People who have mild hemolytic anemia often have no signs or symptoms. More severe hemolytic anemia may cause many signs and symptoms, and they may be serious.
Many of the signs and symptoms of hemolytic anemia apply to all types of anemia.
The most common symptom of all types of anemia is fatigue (tiredness). Fatigue occurs because your body doesn't have enough red blood cells to carry oxygen to its various parts.
A low red blood cell count also can cause shortness of breath, dizziness, headache, coldness in your hands and feet, pale skin, and chest pain.
A lack of red blood cells also means that your heart has to work harder to move oxygen-rich blood through your body. This can lead to arrhythmias (irregular heartbeats), a heart murmur, an enlarged heart, or even heart failure.
Jaundice refers to a yellowish color of the skin or whites of the eyes. When red blood cells die, they release hemoglobin into the bloodstream.
The hemoglobin is broken down into a compound called bilirubin, which gives the skin and eyes a yellowish color. Bilirubin also causes urine to be dark yellow or brown.
Gallstones or an enlarged spleen may cause pain in the upper abdomen. High levels of bilirubin and cholesterol (from the breakdown of red blood cells) can form into stones in the gallbladder. These stones can be painful.
The spleen is an organ in the abdomen that helps fight infection and filters out old or damaged blood cells. In hemolytic anemia, the spleen may be enlarged, which can be painful.
In people who have sickle cell anemia, the sickle-shaped cells can clog small blood vessels and block blood flow. This can cause leg sores and pain throughout the body.
You may develop hemolytic anemia due to a blood transfusion. This can happen if the transfused blood is a different blood type than your blood.
Signs and symptoms of a severe reaction to a transfusion include fever, chills, low blood pressure, and shock. (Shock is a life-threatening condition that occurs if the body isn't getting enough blood flow.)
Your doctor will diagnose hemolytic anemia based on your medical and family histories, a physical exam, and test results.
Primary care doctors, such as a family doctor or pediatrician, may help diagnose and treat hemolytic anemia. Your primary care doctor also may refer you to a hematologist. This is a doctor who specializes in diagnosing and treating blood diseases and disorders.
Doctors and clinics that specialize in treating inherited blood disorders, such as sickle cell anemia and thalassemias, also may be involved.
If your hemolytic anemia is inherited, you may want to consult a genetic counselor. A counselor can help you understand your risk of having a child who has the condition. He or she also can explain the choices that are available to you.
To find the cause and severity of hemolytic anemia, your doctor may ask detailed questions about your symptoms, personal medical history, and your family medical history.
He or she may ask whether:
Your doctor will do a physical exam to check for signs of hemolytic anemia. He or she will try to find out how severe the condition is and what's causing it.
The exam may include:
Many tests are used to diagnose hemolytic anemia. These tests can help confirm a diagnosis, look for a cause, and find out how severe the condition is.
Often, the first test used to diagnose anemia is a complete blood count (CBC). The CBC measures many parts of your blood.
This test checks your hemoglobin and hematocrit (hee-MAT-oh-crit) levels. Hemoglobin is an iron-rich protein in red blood cells that carries oxygen to the body. Hematocrit is a measure of how much space red blood cells take up in your blood. A low level of hemoglobin or hematocrit is a sign of anemia.
The normal range of these levels may vary in certain racial and ethnic populations. Your doctor can explain your test results to you.
The CBC also checks the number of red blood cells, white blood cells, and platelets in your blood. Abnormal results may be a sign of hemolytic anemia, a different blood disorder, an infection, or another condition.
Finally, the CBC looks at mean corpuscular (kor-PUS-kyu-lar) volume (MCV). MCV is a measure of the average size of your red blood cells. The results may be a clue as to the cause of your anemia.
If the CBC results confirm that you have anemia, you may need other blood tests to find out what type of anemia you have and how severe it is.
Reticulocyte count. A reticulocyte (re-TIK-u-lo-site) count measures the number of young red blood cells in your blood. The test shows whether your bone marrow is making red blood cells at the correct rate.
People who have hemolytic anemia usually have high reticulocyte counts because their bone marrow is working hard to replace the destroyed red blood cells.
Peripheral smear. For this test, your doctor will look at your red blood cells through a microscope. Some types of hemolytic anemia change the normal shape of red blood cells.
Coombs' test. This test can show whether your body is making antibodies (proteins) to destroy red blood cells.
Haptoglobin, bilirubin, and liver function tests. When red blood cells break down, they release hemoglobin into the bloodstream. The hemoglobin combines with a chemical called haptoglobin. A low level of haptoglobin in the bloodstream is a sign of hemolytic anemia.
Hemoglobin is broken down into a compound called bilirubin. High levels of bilirubin in the bloodstream may be a sign of hemolytic anemia. High levels of this compound also occur with some liver and gallbladder diseases. Thus, you may need liver function tests to find out what's causing the high bilirubin levels.
Hemoglobin electrophoresis. This test looks at the different types of hemoglobin in your blood. It can help diagnose the type of anemia you have.
Testing for paroxysmal nocturnal hemoglobinuria (PNH). In PNH, the red blood cells are missing certain proteins. The test for PNH can detect red blood cells that are missing these proteins.
Osmotic fragility test. This test looks for red blood cells that are more fragile than normal. These cells may be a sign of hereditary spherocytosis (an inherited type of hemolytic anemia).
Testing for glucose-6-phosphate dehydrogenase (G6PD) deficiency. In G6PD deficiency, the red blood cells are missing an important enzyme called G6PD. The test for G6PD deficiency looks for this enzyme in a sample of blood.
A urine test will look for the presence of free hemoglobin (a protein that carries oxygen in the blood) and iron.
Bone marrow tests show whether your bone marrow is healthy and making enough blood cells. The two bone marrow tests are aspiration (as-pi-RA-shun) and biopsy.
For a bone marrow aspiration, your doctor removes a small amount of fluid bone marrow through a needle. The sample is examined under a microscope to check for faulty cells.
A bone marrow biopsy may be done at the same time as an aspiration or afterward. For this test, your doctor removes a small amount of bone marrow tissue through a needle. The tissue is examined to check the number and type of cells in the bone marrow.
You may not need bone marrow tests if blood tests show what's causing your hemolytic anemia.
Because anemia has many causes, you may have tests for conditions such as:
All States mandate screening for sickle cell anemia as part of their newborn screening programs. Some States also mandate screening for G6PD deficiency. These inherited types of hemolytic anemia can be detected with routine blood tests.
Diagnosing these conditions as early as possible is important so that children can get proper treatment.
Treatments for hemolytic anemia include blood transfusions, medicines, plasmapheresis (PLAZ-meh-feh-RE-sis), surgery, blood and marrow stem cell transplants, and lifestyle changes.
People who have mild hemolytic anemia may not need treatment, as long as the condition doesn't worsen. People who have severe hemolytic anemia usually need ongoing treatment. Severe hemolytic anemia can be fatal if it's not properly treated.
The goals of treating hemolytic anemia include:
Treatment will depend on the type, cause, and severity of the hemolytic anemia you have. Your doctor also will consider your age, overall health, and medical history.
If you have an inherited form of hemolytic anemia, it's a lifelong condition that may require ongoing treatment. If you have an acquired form of hemolytic anemia, it may go away if its cause can be found and corrected.
Blood transfusions are used to treat severe or life-threatening hemolytic anemia.
A blood transfusion is a common procedure in which blood is given to you through an intravenous (IV) line in one of your blood vessels. Transfusions require careful matching of donated blood with the recipient's blood.
For more information, go to the Health Topics Blood Transfusion article.
Medicines can improve some types of hemolytic anemia, especially autoimmune hemolytic anemia (AIHA). Corticosteroid medicines, such as prednisone, can stop your immune system from, or limit its ability to, make antibodies (proteins) against red blood cells.
If you don't respond to corticosteroids, your doctor may prescribe other medicines to suppress your immune system. Examples include the medicines rituximab and cyclosporine.
If you have severe sickle cell anemia, your doctor may recommend a medicine called hydroxyurea. This medicine prompts your body to make fetal hemoglobin. Fetal hemoglobin is the type of hemoglobin that newborns have.
In people who have sickle cell anemia, fetal hemoglobin helps prevent red blood cells from sickling and improves anemia.
Plasmapheresis is a procedure that removes antibodies from the blood. For this procedure, blood is taken from your body using a needle inserted into a vein.
The plasma, which contains the antibodies, is separated from the rest of the blood. Then, plasma from a donor and the rest of the blood is put back in your body.
This treatment may help if other treatments for immune hemolytic anemia don't work.
Some people who have hemolytic anemia may need surgery to remove their spleens. The spleen is an organ in the abdomen. A healthy spleen helps fight infection and filters out old or damaged blood cells.
An enlarged or diseased spleen may remove more red blood cells than normal, causing anemia. Removing the spleen can stop or reduce high rates of red blood cell destruction.
In some types of hemolytic anemia, such as thalassemias, the bone marrow doesn't make enough healthy red blood cells. The red blood cells it does make may be destroyed before their normal lifespan is over. Blood and marrow stem cell transplants may be used to treat these types of hemolytic anemia.
A blood and marrow stem cell transplant replaces damaged stem cells with healthy ones from another person (a donor).
During the transplant, which is like a blood transfusion, you get donated stem cells through a tube placed in a vein. Once the stem cells are in your body, they travel to your bone marrow and begin making new blood cells.
For more information, go to the Health Topics Blood and Marrow Stem Cell Transplant article.
If you have AIHA with cold-reactive antibodies, try to avoid cold temperatures. This can help prevent the breakdown of red blood cells. It's very important to protect your fingers, toes, and ears from the cold.
To protect yourself, you can:
People born with glucose-6-phosphate dehydrogenase (G6PD) deficiency can avoid substances that may trigger anemia. For example, avoid fava beans, naphthalene (a substance found in some moth balls), and certain medicines (as your doctor advises).
You can't prevent inherited types of hemolytic anemia. One exception is glucose-6-phosphate dehydrogenase (G6PD) deficiency.
If you're born with G6PD deficiency, you can avoid substances that may trigger the condition. For example, avoid fava beans, naphthalene (a substance found in some moth balls), and certain medicines (as your doctor advises).
Some types of acquired hemolytic anemia can be prevented. For example, reactions to blood transfusions, which can cause hemolytic anemia, can be prevented. This requires careful matching of blood types between the blood donor and the recipient.
Prompt and proper prenatal care can help you avoid the problems of Rh incompatibility. This condition can occur during pregnancy if a woman has Rh-negative blood and her baby has Rh-positive blood. "Rh-negative" and "Rh-positive" refer to whether your blood has Rh factor. Rh factor is a protein on red blood cells.
Rh incompatibility can lead to hemolytic anemia in a fetus or newborn.
Hemolytic anemia can be mild or severe. Inherited forms of hemolytic anemia are lifelong conditions and may require ongoing treatment. Acquired forms of the condition may go away if the cause is found and corrected.
If you have hemolytic anemia, take good care of your health. See your doctor regularly and follow your treatment plan. Talk with your doctor about whether you should get a yearly flu shot and a pneumonia vaccine.
Ask your doctor about ways to reduce your chance of getting an infection, such as:
You can take steps to stay healthy. For example, try to get plenty of rest.
If you have cold-reactive autoimmune hemolytic anemia, stay away from cold temperatures. During cold weather, wear a hat, scarf, and a warm coat. When taking cold food out of the refrigerator or freezer, wear gloves. Turn down air conditioning or dress warmly while in air-conditioned spaces. Warm up the car before driving in cold weather.
If you have glucose-6-phosphate dehydrogenase (G6PD) deficiency, avoid substances that can trigger anemia. For example, avoid fava beans, naphthalene (a substance found in some moth balls), and certain medicines (as your doctor advises).
Ask your doctor what types and amounts of physical activity are safe for you. You may want to avoid certain sports or activities that could worsen your condition or lead to complications.
Parents of children who have hemolytic anemia usually want to learn as much as possible about the condition from their child's health care team.
You can be an active partner in caring for your child. Talk with your child's health care team about treatment, diet, and physical activity. Learn the signs of worsening anemia and possible complications so you can contact your child's doctor.
You may want to educate family members, friends, and your child's classmates about hemolytic anemia. You also may want to tell your child's teachers or other caregivers about the condition. Let them know whether your child has any special limitations or restrictions.
Family members, friends, teachers, and caregivers can provide a network of support to help your child cope with his or her hemolytic anemia.
Allow teenagers to have input in decisions about their health. This encourages them to take an active role in their health care. Help them understand lifestyle restrictions and their medical needs so they can better cope with having hemolytic anemia.
The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.
Researchers have learned a lot about anemia and other blood diseases and conditions over the years. That knowledge has led to advances in medical knowledge and care.
Many questions remain about blood diseases and conditions, including hemolytic anemia. The NHLBI continues to support research aimed at learning more about these illnesses.
For example, NHLBI-supported research on hemolytic anemia includes studies that explore:
Much of this research depends on the willingness of volunteers to take part in clinical trials. Clinical trials test new ways to prevent, diagnose, or treat various diseases and conditions.
For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.
By taking part in a clinical trial, you can gain access to new treatments before they're widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don't directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.
If you volunteer for a clinical trial, the research will be explained to you in detail. You'll learn about treatments and tests you may receive, and the benefits and risks they may pose. You'll also be given a chance to ask questions about the research. This process is called informed consent.
If you agree to take part in the trial, you'll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.
For more information about clinical trials related to hemolytic anemia, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:
For more information about clinical trials for children, visit the NHLBI's Children and Clinical Studies Web page.
Source: NHLBI, NIH