Anemia is a condition in which red blood cells or the hemoglobin (the oxygen-carrying substance) in red blood cells is abnormally low.
Hemoglobin helps red blood cells carry and deliver oxygen to the rest of the body. The amount of hemoglobin and number of red blood cells can be decreased by many different conditions. Anemia results in a decreased ability of the blood to carry oxygen to the tissues of the body, which often causes symptoms.
Signs and symptoms depend on the cause of the anemia. Mild anemia may cause few or no symptoms.
Common signs and symptoms of anemia include: paleness of the skin, inside of the mouth, and eyes, also called pallorfatigue or tirednessweaknessreduced ability to exerciseincreased heart rate with activityan abnormal awareness of the heartbeat, called palpitations, which may be unusually hard or fastshortness of breath or breathlessnessloss of appetitechest painmental changes, including memory loss, confusion, and depressiondelayed growth and development in children
Because there are different types of anemia, the causes and risks will vary.
Some of the causes of anemia may include: deficiency of certain minerals or vitamins, such as iron, which is called iron deficiency anemia. Anemia due to vitamin B12 deficiency is called pernicious anemia. Lack of folic acid, an important nutrient in vegetables, can also cause anemia.inherited conditions, such as sickle cell disease, thalassemia, and glucose-6-phosphate dehydrogenase deficiencyautoimmune disorders, conditions in which a person's immune system attacks his or her own body. In this case, the immune system attacks and destroys the red blood cells. Examples of these disorders include autoimmune hemolytic anemia and systemic lupus erythematosus (SLE).drugs or medications, such as alcohol, the antibiotic penicillin, or the high blood pressure drug methyldopa (i.e., Aldomet)blood loss, which can occur due to menstruation, injury, surgery, colon cancer, and other conditionspregnancytimes of rapid growth, during early childhood, for examplekidney failure, such as chronic renal failurechronic disorders, especially disorders that cause inflammation. Examples are cancer, the infections tuberculosis and HIV, and rheumatoid arthritis. Hormone imbalances, such as a low thyroid hormone level, called hypothyroidism, are another cause. Anemia from these causes is called anemia of chronic disease.damage to or other problems in the bone marrow. Bone marrow is a type of tissue in the middle of certain bones that makes red blood cells. Cancer, medications, infections, and other conditions can affect the marrow. There are different names for this type of anemia depending on the exact type. Examples include aplastic anemia and myelophthisic anemia.
Many cases cannot be prevented. Eating a well-balanced diet can help prevent some cases caused by low levels of vitamins or minerals. Avoiding alcohol can prevent cases from alcohol abuse.
Diagnosis begins with the history and physical exam. Blood tests are used to confirm the diagnosis. A complete blood count (CBC) will show a lower-than-normal amount of hemoglobin in the blood. The number of red blood cells may also be low. Looking at blood cells with a microscope can help figure out the cause in some cases. The size and shape of the blood cells often changes based on the type of anemia.
Other blood tests may also be done, depending on the suspected cause. For example, the blood levels of iron, folate, or vitamin B12 can be checked if these causes are suspected. The stool may also be tested to check for blood loss. This is known as a fecal occult blood test. Other blood, urine, or imaging tests may also be used.
In some cases, a procedure called bone marrow biopsy may be advised. This involves inserting a special needle through the skin of the buttocks into the back of the hipbone. The needle is pushed into the middle of the bone, which contains bone marrow. A sample of marrow is taken out with the needle. The sample is then sent to the lab for examination and other testing.
Severe anemia can make a person too weak to perform normal activities. It can even cause heart attacks, other organ damage, and death. However, most long-term effects of anemia depend on the cause. For example, cases due to low levels of vitamins or minerals can often be treated and resolve without long-term effects. On the other hand, cases due to cancer may result in death.
Anemia is not contagious, but it can be inherited. People with inherited forms of anemia, such as sickle cell disease, may want to seek genetic counseling. This can help people understand the risk of passing anemia on to their children.
In severe cases, blood transfusions may be needed. High levels of oxygen can also be given to help the person breathe until the blood count can be raised. More specific treatments depend on the cause. For example, pills or injections may replace low levels of vitamins or minerals.
If anemia is caused by blood loss, the blood loss needs to be stopped. Sometimes surgery is needed to stop bleeding, such as bleeding from the bowels or heavy menstrual bleeding. Antibiotics may be needed if a long-term infection is the cause. If alcohol or medications caused the anemia, stopping the drug may be all that is needed.
In cases of anemia that occur because blood cells are being destroyed in the spleen, surgery to remove the spleen is advised. This is known as a splenectomy. Other treatments are also possible.
Side effects depend on the treatments used. Blood transfusions may cause allergic reactions or infections. Surgery can be complicated by bleeding, infection, or a reaction to anesthesia. All medications have possible side effects. For example, antibiotics can cause stomach upset, allergic reactions, or other effects.
A person's progress after treatment depends on the cause of the anemia and the response to treatment. For example, cases due to blood loss or certain infections may be "cured" by treatment. In some people with inherited types of anemia, the anemia never goes away. These people often need further monitoring and treatment. A person with cancer may die if treatment is not successful.
If symptoms continue or get worse, the healthcare professional should be notified. It is important to watch for bleeding, weakness, and other unusual symptoms. The hemoglobin level in the blood may be monitored with blood tests.
Mayo Clinic Family Health Book, David E. Larson, 1996