Anemia is a lack of red blood cells and/or the iron-rich molecule in red blood cells (hemoglobin) that carries oxygen throughout the body and gives blood its red color. There are more than 100 types of anemia. Some forms of anemia are temporary while other types can be a long-term disease. Most types of anemia can be successfully treated, depending on the underlying cause. Untreated anemia, however, and some chronic forms may be damaging or even life-threatening.

Severe anemia has been associated with various forms of heart disease. Because the body is receiving less oxygen, the heart responds by working harder to pump more blood through the body. In cases of severe anemia, the overworked heart may begin to dilate, causing an enlarged heart or cardiomyopathy. This may eventually lead to heart failure.

Mild forms of anemia may produce no significant symptoms. However, individuals with more severe anemia may experience chronic fatigue, weakness, paleness and shortness of breath, especially when active. Anyone who has these symptoms should see their physician for an evaluation.

There are more than 100 types of anemia, and not all of them are treated in the same way. If the anemia is “secondary to,” or caused by another chronic disease, such as kidney disease, the goal is to treat the underlying disease. By contrast, if the anemia is due to abnormally heavy bleeding, such as during menstruation or surgery, a physician may recommend certain dietary changes. Iron supplements should be avoided unless prescribed by a physician, because an excess level of iron could damage the heart or other vital organs.

 

Anemia is a lack of red blood cells and/or the iron-rich molecule in red blood cells (hemoglobin) that carries oxygen throughout the body and gives blood its red color. If the body does not have enough oxygen, the muscles and organs cannot function properly, which can lead to fatigue and other symptoms of anemia.

Anemia may be caused when the bone marrow, which produces new red blood cells to replace the normal, daily destruction of old ones, cannot produce enough new red blood cells to keep up with the body's demand. It may also occur when the red blood cells are abnormally short-lived. Alternatively, it may be caused by a lack of available hemoglobin on the existing red blood cells.

Red blood cells are produced in the bone marrow, which is the soft, inner part of the bones. Besides red blood cells, the bone marrow produces white blood cells, which are part of the immune system, and platelets, which help repair damaged blood vessels.

The average normal blood hemoglobin level for adults for men is 14 to 17 grams/deciliter (g/dL) and 12 to 15 g/dL for women. Anemia may be defined as a blood hemoglobin level under 12 grams/deciliter. However, many individuals do not experience symptoms of anemia until their hemoglobin level drops below 10 g/dL especially if the decline has been gradual over weeks to months.

Anemia is not always a primary disease but can be a sign of another disease process. It can be either chronic (developing over a long period of time) or acute (rapid onset). While anemia can be linked to more than 100 causes, the three basic reasons for the condition are:

• The body is losing red blood cells (bleeding)
• The body is not producing enough red blood cells
• The body’s red blood cells are being destroyed (e.g. antibodies, chemicals)

Anemia is a common condition, particularly among:

• Pregnant women
• Women who have a heavy menstrual flow
• Infants
• Older adults with poor nutrition
• African Americans
• Alaskan natives
• Native Americans
• Immigrants from developing countries
• Individuals of lower socioeconomic status

Anemia may be caused by a variety of factors, including a lack of iron, a lack of vitamin B-12, certain prescription drugs (e.g., antibiotics or medications to treat AIDS), antacids, radiation therapy, chemotherapy, pregnancy, heavy menstrual flow or other bleeding, and certain chronic medical conditions. Although most cases of anemia can be cured with treatment, some cases are due to medical conditions that cannot be changed (e.g., sickle cell anemia, thalassemia).

Severe cases of anemia have been associated with a number of heart conditions, including:

• Heart failure. Many heart failure patients also have anemia, which tends to worsen as the heart failure progresses. Studies indicate that treating anemia in heart failure patients can significantly improve heart function and reduce the number of hospitalizations. Furthermore, in some cases severe anemia can actually cause heart failure because it forces the heart to work harder in order to circulate a lower number of red blood cells throughout the body.
  
  
• Cardiomyopathy or enlarged heart. Because severe cases of anemia can cause the heart to work harder, the condition can lead to an enlargement of the entire heart or heart muscle. Over time, cardiomyopathy can develop into heart failure.
  
  
• Bacterial endocarditis. Mild anemia may be detected in patients who have this infection of the lining of the heart and heart valves.
  
  
  
  
• Cancer of the heart. Although rare, anemia may be associated with a tumor in either of the upper chambers of the heart (atria).

Studies have indicated that individuals with anemia may have a 40 percent greater risk of having a heart attack, developing heart disease or needing a procedure to clean the arteries than those without the blood disorder.

Anemia may also increase risks for patients undergoing heart surgery, especially older patients. When present for more than two days after heart surgery, anemia has also been associated with an increased risk of complications or even death in older people.

There are more than 100 types of anemia. Some of the most common include:

• Iron deficiency anemia. This form of anemia is by far the most common. Iron is necessary for the bone marrow to produce hemoglobin. Without this essential mineral, the body fails to produce enough hemoglobin for red blood cells. In addition to food, the usual way for the body to obtain iron is to recycle the iron from blood cells that have died and use it to create new blood cells. Thus, when blood is lost, so is the iron. This process explains why an iron-poor diet, heavy menstrual periods or a growing fetus in a pregnant woman can cause iron deficiency anemia. In men, iron deficiency anemia means that bleeding has occurred somewhere in his body.
  
  
• Sickle cell anemia. More than 70,000 Americans have sickle cell anemia, making it the most common inherited blood disorder in the United States, according to the National Institutes of Health (NIH). This condition disproportionately affects African Americans at a rate of one out of every 500. Sickle cell anemia is an inherited disease marked by a chronic shortage of red blood cells due to a defective form of hemoglobin.
  
  
• Vitamin deficiency anemia. In order to produce red blood cells, the body requires vitamin B12, folic acid and other key nutrients. A diet that is lacking in these essential nutrients can lead to decreased production of red blood cells. Intestinal disorders that reduce the amount of nutrients the body can absorb are a common cause of this type of anemia. The category for all vitamin deficiency anemias is megaloblastic anemias. With this group, the bone marrow of affected individuals produces large, irregular red blood cells (megaloblasts). Examples of vitamin deficiency anemia include megaloblastic anemia and pernicious anemia.
  
  
• Hemolytic anemias. This group of anemias develops when red blood cells are abnormally destroyed within the body. Autoimmune diseases and certain blood disorders can cause hemolytic anemias. Some medications, including antibiotics, can also break down red blood cells causing this condition.
  
  
• Anemias associated with bone marrow disease. The production of blood in the bone marrow can be affected by a variety of diseases, including leukemia, myelodysplasia (MDS, a pre-leukemia condition), multiple myeloma, myeloproliferative disorders, lymphoma and metastatic cancer. The severity of these types of anemias can range from a mild alteration to a potentially fatal shutdown in the production of blood.
  
  
• Aplastic anemia. This rare form of anemia occurs in one to two people for every million residents of the United States, according to the American Cancer Society (ACS). It is seen more often in developing countries where there is greater exposure to toxic chemicals. In this form of anemia, the bone marrow does not make blood cells. While aplastic anemia can be a sign of certain cancers that affect bone marrow (such as leukemia), it is not a type of cancer itself. Exposure to chemicals, such as benzene, as well as chemotherapy drugs and radiation treatment, can cause this type of anemia. It can also be a primary immune disease.
  
  
• Idiopathic anemia. Despite their best efforts, physicians are sometimes unable to determine the cause of anemia in a patient. These cases are labeled idiopathic anemias. These patients should be followed at regular intervals for delayed manifestations of a cancer or other cause of anemia.

There are many other types of anemia which affect a smaller number of people and have an abnormal form of hemoglobin. Thalassemia is one example of an inherited blood disorder that causes mild to severe anemia. This blood disorder is found among individuals of Mediterranean descent, such as Italians and Greeks. These hereditary anemias are called hemoglobinopathics.

Anemia may be difficult to identify at first because the initial symptoms tend to be mild. Also, if the anemia develops gradually, the body will adjust to the decreased level of oxygen, possibly masking some of the symptoms. However, over time, as the anemia worsens, symptoms may emerge, including:

• Fatigue
• Weakness
• Shortness of breath
• Confusion
• Dizziness
• Pale skin
• Feeling cold, especially in the hands or feet

These symptoms result from the lack of oxygen-rich blood to the brain and other areas of the body. In some cases, patients may also show heart-related signs or symptoms of anemia, such as:

• Abnormal heart rhythm (arrhythmia), such as an abnormally fast heartbeat (tachycardia ) or a pounding, galloping heartbeat (palpitations)
  
  
• Heart murmur
  
  
• Chest pain

When diagnosing anemia, a physician will first obtain the patient’s personal and family medical history. The physician will then give the patient a physical examination, listening for a heart murmur and looking for other possible signs of anemia. To help with the diagnosis, the physician will order several blood tests, including:

• Complete blood count (CBC). The CBC includes counts of all three types of blood cells present in a blood sample: red blood cells (RBC), white blood cells (WBC) and platelets (thrombocytes). Anemia is typically confirmed by a low red blood cell count.
  
  
• Hemoglobin count. Hemoglobin is the pigment that carries oxygen on red blood cells and lends the red color to blood cells. Anemia may be diagnosed if the hemoglobin concentration is less than 13.5 grams per milliliter of whole blood (g/dL) in men or 12 g/dL in women.
  
  
• Hematocrit count. A hematocrit count is another way to measure red blood cells by calculating the percent of the blood that is composed of intact red blood cells. A hematocrit count of less than 41 percent in men or 36 percent in women may suggest anemia.

If anemia is present, the physician will next focus on the possible causes. Additional tests may be ordered based on the blood test results:

• If blood tests reveal a low iron level and a low level of ferritin (a protein that stores iron), the physician may order a stool sample to rule out internal bleeding. The physician may also order other gastrointestinal tests, such as an endoscopy.
  
  
• If blood tests reveal a low iron level but a normal ferritin level, then the physician may suspect a chronic illness (e.g., rheumatoid arthritis) that is causing the anemia.
  
  
• If blood tests reveal a normal iron level and a normal ferritin level, then the physician may order additional blood tests to look for a vitamin deficiency.
  
  
• A bone marrow sample may need to be taken to see if the marrow has been replaced by fat cells or cancer cells.
  
  
• A biopsy may be necessary if cancer is suspected, but this is rare.

Treatment for anemia begins by identifying and treating any underlying cause. For example, anemia is commonly caused by chronic kidney disease, thus treating the kidney disease may resolve the anemia.

If the anemia is not caused by another disease, it may be treated with supplements, injections of specific vitamins and/or increased intake of nutrient-rich foods. Other treatments for anemia include:

• Blood transfusions. This may be used to replace the patients blood with healthy blood of the same blood type. However, precautions need to be taken to make sure that iron levels do not rise to dangerous levels while patients receive blood transfusions.
  
  
• Medications. Several medications may be used to treat anemia, including steroids, which reduce misguided immune responses from attacking red blood cells.
  
  
• Surgery. If the spleen is destroying red blood cells faster than bone marrow can produce them, the spleen may need to be removed.

Research is ongoing to determine the best treatments for different types of anemia among certain groups. A recent study found that African-American women with sickle cell anemia responded twice as well as their male counterparts to injections of nitric oxide (a substance that dilates arteries, allowing blood to flow more freely).

Although not yet a treatment option, gene therapy may hold promise in the treatment of some types of anemia. Researchers have successfully corrected sickle cell anemia in mice using gene therapy. Eating a balanced, heart-healthy diet can help prevent the most common forms of anemia. Other types of anemia are present since birth, or develop for unknown reasons, and have no known prevention strategies.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to anemia and the heart:

1. Why do you suspect I have anemia?
   
   
2. What do you think is causing my anemia?
   
   
3. What tests will be used to diagnose my condition?
   
   
4. Has anemia affected my heart in any way?
   
   
5. What are my heart risks from my anemia?
   
   
6. When and from whom will I receive the results of my blood tests?
   
   
7. What is my red blood cell count? How low is my hemoglobin and hematocrit?
   
   
8. Is my anemia temporary or due to a chronic condition?
   
   
9. Could I be anemic as a result of any of the medications I am taking?
   
   
10. Could my anemia be the result of a larger medical condition?
    
    
11. Are there any lifestyle changes I could make to improve my anemia?
    
    
12. Should I be taking iron or any other supplements?
    
    
13. Will any medications improve my anemia?
    
    
14. How will my anemia be monitored in the future?
    
    
15. Could anemia interfere with my pregnancy in any way?
    
    
16. If my anemia is from a genetic condition, will my children have it also?