Anemia



Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues.

Causes, incidence, and risk factors

While many parts of the body help make red blood cells, most of the work is done in the bone marrow. Bone marrow is the soft tissue in the center of bones that helps form blood cells.
Healthy red blood cells last between 90 and 120 days. Parts of your body then remove old blood cells. A hormone called erythropoietin made in your kidneys signals your bone marrow to make more red blood cells.
Hemoglobin is the oxygen-carrying protein inside red blood cells. It gives red blood cells their red color. People with anemia do not have enough hemoglobin.
Possible causes of anemia include:
  • Certain medications
  • Chronic diseases such as cancer, ulcerative colitis, or rheumatoid arthritis
  • Genetics: Some forms of anemia, such as thalassemia, can be inherited
  • Kidney failure
  • Blood loss (for example, from heavy menstrual periods or stomach ulcers)
  • Poor diet
  • Pregnancy
  • Problems with bone marrow such as lymphoma, leukemia, or multiple myeloma
  • Problems with the immune system that cause the destruction of blood cells (hemolytic anemia)
  • Surgery to the stomach or intestines that reduces the absorption of iron, vitamin B12, or folic acid
  • Too little thyroid hormone (underactive thyroid, or hypothyroidism)
  • Testosterone deficiency

Symptoms

Possible symptoms include:
Some types of anemia may have other symptoms, such as:

Signs and tests

The doctor will perform a physical examination, and may find:
  • Pale skin
  • Rapid heart rate
  • Heart murmur
Some types of anemia may cause other findings on a physical exam.
Blood tests used to diagnose some common types of anemia may include:
Other tests may be done to identify medical problems that can cause anemia.

Treatment

Treatment should be directed at the cause of the anemia, and may include:
  • Blood transfusions
  • Corticosteroids or other medicines that suppress the immune system
  • Erythropoietin, a medicine that helps your bone marrow make more blood cells
  • Supplements of iron, vitamin B12, folic acid, or other vitamins and minerals

Expectations (prognosis)

The outlook depends on the cause.

Complications

Severe anemia can cause low oxygen levels in vital organs such as the heart, and can lead to a heart attack.



Anemia - B12 deficiency

Macrocytic anemia

Vitamin B12 deficiency anemia is a low red blood cell count due to a lack of vitamin B12.  Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues.

Causes, incidence, and risk factors

Your body needs vitamin B12 to make red blood cells. In order to provide vitamin B12 to your cells:
  • You must eat plenty of foods that contain vitamin B12, such as meat, poultry, shellfish, eggs, and dairy products.
  • Your body must absorb enough vitamin B12. A special protein, called intrinsic factor, helps your body do this. This protein is released by cells in the stomach.
A lack of vitamin B12 may be due to dietary factors, including:
  • Eating a vegetarian diet
  • Poor diet in infants
  • Poor nutrition during pregnancy
Certain health conditions can make it difficult for your body to absorb enough vitamin B12. They include:
  • Chronic alcoholism
  • Crohn's disease, celiac disease, infection with the fish tapeworm, or other problems that make it difficult for your body to digest foods
  • Pernicious anemia, a type of vitamin B12 anemia that occurs when your body destroys cells that make intrinsic factor
  • Surgeries that remove certain parts of your stomach or small intestine, such as some weight-loss surgeries
  • Taking antacids and other heartburn medicines for a long period of time

Symptoms

You may not have symptoms. Symptoms may be mild.
Symptoms can include:
If you have low vitamin B12 levels for a long time, you can have nerve damage. Symptoms of nerve damage include:
  • Confusion or change in mental status (dementia) in severe cases
  • Depression
  • Loss of balance
  • Numbness and tingling of hands and feet

Signs and tests

The doctor or nurse will perform a physical exam. This may reveal problems with your reflexes.
Tests that may be done include:
This list may not be all-inclusive.
Other procedures that may be done include:

Treatment

Treatment depends on the cause of B12 deficiency anemia. For treatment of anemia due to a lack of intrinsic factor, see: Pernicious anemia
The goal of treatment is to increase your vitamin B12 levels.
  • Treatment may include a shot of vitamin B12 once a month. Persons with severely low levels of B12 may need more shots in the beginning. You may need shots every month for the rest of your life.
  • Some patients may also need to take vitamin B12 supplements by mouth. For some people, high-dose vitamin B12 tablets taken by mouth work well, and shots are not needed.
 Treatment may no longer be needed after Crohn's disease, celiac disease, or alcoholism is properly treated.
Your doctor or nurse will also recommend eating a well-balanced diet.

Expectations (prognosis)

With treatment, patients usually do well.
Long-term vitamin B12 deficiency can cause nerve damage. This may be permanent if you do not start treatment within 6 months of when your symptoms begin.

Complications

Women with low B12 levels may have a falsely abnormal Pap smear. That is because vitamin B12 affects the way certain cells, called epithelial cells, look.

Calling your health care provider

Call your health care provider if you have any of the symptoms of anemia.

Prevention

You can prevent anemia caused by a lack of vitamin B12 by following a well-balanced diet.
Shots of vitamin B12 can prevent anemia after surgeries known to cause vitamin B12 deficiency.
Early diagnosis and prompt treatment can reduce or prevent complications related to low vitamin B12 levels.




Folate-deficiency anemia

Last reviewed: February 8, 2012.
Folate-deficiency anemia is a decrease in red blood cells (anemia) due to a lack of folate. Folate is a type of B vitamin. It is also called folic acid.
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues.

Causes, incidence, and risk factors

Folate (folic acid) is needed for red blood cells to form and grow. You can get folate by eating green leafy vegetables and liver. However, your body does not store folate in large amounts. So, you need to eat plenty of folate-rich foods to maintain normal levels of this vitamin.
In folate-deficiency anemia, the red  blood cells are abnormally large. Such cells are called megalocytes. They are also called megaloblasts. They are seen in the bone marrow. This is why this anemia is also called megaloblastic anemia.
Causes of this type of anemia include:
The following raise your risk for this type of anemia:
  • Alcoholism
  • Eating overcooked food
  • Poor diet (often seen in the poor, the elderly, and people who do not eat fresh fruits or vegetables)
  • Pregnancy
Folic acid is needed to help a baby in the womb grow properly. Too little folic acid during pregnancy may lead to birth defects in a baby. For more information see: Folic acid and birth defect prevention

Symptoms

Signs and tests

The doctor or nurse will perform a physical exam. Tests that may be done include:
Rarely, a bone marrow examination may be done.

Treatment

The goal is to identify and treat the cause of the folate deficiency.
You may receive folic acid supplements, taken by mouth or given through a vein. If you have low folate levels because of a problem with your intestines, you make need treatment for the rest of your life.
Diet changes can help boost your folate level. Eat more green, leafy vegetables and citrus fruits.

Expectations (prognosis)

Anemia usually responds well to treatment within 2 months.

Complications

Symptoms of anemia can cause discomfort. In pregnant women, folate deficiency has been associated with neural tube or spinal defects (such as spina bifida) in the infant.
Other, more severe complications may include:

Calling your health care provider

Call for an appointment with your health care provider if you have symptoms of folate deficiency anemia.

Prevention

Eating plenty of folate rich foods can help prevent this condition.
Experts recommend that women take 400 micrograms (mcg) of folic acid every day before you get pregnant through the first 3 months of pregnancy.





Iron deficiency anemia

Anemia - iron deficiency
Last reviewed: February 28, 2011.
Anemia is a condition in which the body does not have enough healthy red blood cells. Iron is an important building block for red blood cells.
When your body does not have enough iron, it will make fewer red blood cells or red blood cells that are too small. This is called iron deficiency anemia.

Causes, incidence, and risk factors

Iron deficiency anemia is the most common form of anemia.
Red blood cells bring oxygen to the body's tissues. Healthy red blood cells are made in your bone marrow. Red blood cells move through your body for 3 to 4 months. Parts of your body then remove old blood cells.
Iron is a key part of red blood cells. Without iron, the blood cannot carry oxygen effectively. Your body normally gets iron through your diet and by re-using iron from old red blood cells.
You get iron deficiency anemia when your body's iron stores run low. You can get iron deficiency if:
  • You lose more blood cells and iron than your body can replace
  • Your body does not do a good job of absorbing iron
  • Your body is able to absorb iron, but you are not eating enough foods with iron in them
  • Your body needs more iron than normal (such as if you are pregnant or breastfeeding)
Iron loss can be due to bleeding. Common causes of bleeding are:
The body may not absorb enough iron in the diet due to:
You may not get enough iron in the diet if:
  • You are a strict vegetarian
  • You are an older adult and do not eat a full diet

Symptoms

You may have no symptoms if the anemia is mild.
Most of the time, symptoms are mild at first and develop slowly. Symptoms may include:
  • Feeling grumpy
  • Feeling weak or tired more often than usual, or with exercise
  • Headaches
  • Problems concentrating or thinking
As the anemia gets worse, symptoms may include:
Symptoms of the conditions that cause iron deficiency anemia include:
  • Dark, tar-colored stools or blood
  • Heavy menstrual bleeding (women)
  • Pain in the upper belly (from ulcers)
  • Weight loss (in people with cancer)

Signs and tests

To diagnose anemia, your doctor may order these blood tests:
Tests to check iron levels in your blood include:
Tests that may be done to look for the cause of iron deficiency:

Treatment

Taking supplements and eating iron-rich foods are important parts of treating iron deficiency anemia. However, you and your health care provider must first search for the cause of your anemia.
Iron supplements (most often ferrous sulfate) are needed to build up the iron stores in your body.
Patients who cannot take iron by mouth can take it through a vein (intravenous) or by an injection into the muscle.
Pregnant and breastfeeding women will need to take extra iron because their normal diet usually will not provide the amount they need.
The hematocrit should return to normal after 2 months of iron therapy. However, keep taking iron for another 6 - 12 months to replace the body's iron stores in the bone marrow.
Iron-rich foods include:
  • Chicken and turkey
  • Dried lentils, peas, and beans
  • Eggs (yolk)
  • Fish
  • Meats (liver is the highest source)
  • Peanut butter
  • Soybeans
  • Whole-grain bread
Other sources include:
  • Oatmeal
  • Raisins, prunes, and apricots
  • Spinach, kale, and other greens

Expectations (prognosis)

With treatment, the outcome is likely to be good. However, it does depend on the cause. Usually, blood counts will return to normal in 2 months.

Calling your health care provider

Call for an appointment with your health care provider if:
  • You have symptoms of this disorder
  • You notice blood in your stool

Prevention

Everyone's diet should include enough iron. Red meat, liver, and egg yolks are important sources of iron. Flour, bread, and some cereals are fortified with iron. If you aren't getting enough iron in your diet (uncommon in the United States), take iron supplements.
During periods when you need extra iron (such as pregnancy and breastfeeding), increase the amount of iron in your diet or take iron supplements.


Anemia of chronic disease

Anemia of inflammation
Last reviewed: February 28, 2011.
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. There are many types of anemia.
Anemia of chronic disease is a blood disorder that refers to anemia that is found in people with certain long-term (chronic) medical conditions.
See also: Anemia

Causes, incidence, and risk factors

Anemia is a lower-than-normal number of red blood cells in the blood. Certain chronic infections, inflammatory diseases, and other illnesses can affect the body's ability to produce red blood cells.
Conditions that can lead to anemia of chronic disease include:

Symptoms

Anemia of chronic disease is often mild. You may not notice symptoms of anemia.
Symptoms may include:
  • Feeling weak or tired
  • Headache
  • Paleness
  • Shortness of breath

Signs and tests

The doctor will perform a physical examination.
Because anemia may be the first symptom of a serious illness, determining its cause is very important.
Tests that may be done to diagnose anemia or rule out other causes include:

Treatment

The anemia is often mild enough that it requires no treatment, and will likely get better when the disease that is causing it is treated.
The condition is rarely severe enough to require a blood transfusion.
Iron supplements may sometimes be used, but only for patients whose iron levels are low. Taking iron pills when your body does not need it can lead to serious medical problems. Always talk with your health care provider first.
For some conditions, such as chronic kidney disease, medicine called erythropoietin may be given. It stimulates your bone marrow to make more red blood cells.

Expectations (prognosis)

The anemia will improve when the disease that is causing it is successfully treated.

Complications

Discomfort from symptoms is the main complication in most cases. Anemia is associated with a higher risk of death in patients with heart failure.



Hemolytic anemia

Anemia - hemolytic

Hemolytic anemia is a condition in which there are not enough red blood cells in the blood, due to the premature destruction of red blood cells. There are a number of specific types of hemolytic anemia, which are described individually.

Causes, incidence, and risk factors

Hemolytic anemia occurs when the bone marrow is unable to increase production to make up for the premature destruction of red blood cells. If the bone marrow is able to keep up with the early destruction, anemia does not occur (this is sometimes called compensated hemolysis).
There are many types of hemolytic anemia, which are classified by the reason for the premature destruction of red blood cells. The defect may be in the red blood cell itself (intrinsic factors), or outside the red blood cell (extrinsic factors).
Intrinsic factors are often present at birth (hereditary). They include:
  • Abnormalities in the proteins that build normal red blood cells
  • Differences in the protein inside a red blood cell that carries oxygen (hemoglobin)
Extrinsic factors include:
  • Abnormal immune system responses
  • Blood clots in small blood vessels
  • Certain infections
  • Side effects from medications
Types of hemolytic anemia include:

Symptoms

Signs and tests

These are tests for red blood cell destruction (hemolysis). Specific tests can identify the types of hemolytic anemia. They are usually performed when hemolysis is suspected or has been determined.
Directly measuring the red cell life span with radioactive tagging techniques shows a shortened life span.
This disease may also affect the following test results, depending on the specific cause:

Treatment

Treatment depends on the type and cause of the hemolytic anemia. Folic acid, iron replacement, and corticosteroids may be used. In emergencies, a blood transfusion or removal of the spleen (splenectomy) may be necessary.

Expectations (prognosis)

The outcome depends on the type and cause of hemolytic anemia.

Complications

The complications depend on the specific type of hemolytic anemia. Severe anemia can cause cardiovascular collapse (failure of the heart and blood pressure, leading to death). Severe anemias can worsen heart disease, lung disease, or cerebrovascular disease.

Calling your health care provider

Call for an appointment with your health care provider if you develop symptoms of hemolytic anemia.

Prevention

There is no known prevention for hemolytic anemia.
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