| ICD-9-CM: |
| 281 - | Deficiency Anemias, Other |
| 285 - | Anemias, Other and Unspecified |
| 285.1 - | Anemia, Posthemorrhagic, Acute; Anemia Due to Acute Blood Loss |
| 285.9 - | Anemia, Unspecified, NOS, Essential, Normocytic, Not Due to Blood Loss, Profound, Progressive, Secondary |
| 776.5 - | Congenital Anemia |
| Anemia is defined as an abnormally low number of red blood cells, an abnormally low amount of protein inside each red blood cell capable of carrying oxygen (hemoglobin), or an abnormally low measure of red cell mass (hematocrit). In each of these three deficiencies, the oxygen-carrying capacity of the blood is decreased, resulting in less oxygen for body tissues (hypoxia).
Anemia is not a disease but rather a symptom of many conditions or diseases. Causes are grouped into three categories: blood loss, red blood cell destruction, and impaired red blood cell production.
Blood loss can be sudden and acute such as following a traumatic penetrating injury, or it may be slow and chronic such as occurring in chronic gastrointestinal bleeding. Blood clotting disorders like hemophilia also cause excessive bleeding that may lead to anemia. Blood loss due to prolonged, heavy, or frequent menstrual bleeding is another cause of anemia.
Red blood cells may be destroyed or removed from circulation faster than they can be replaced by new cells produced in the bone marrow. This occurs when there are defects within the red blood cell (i.e., in sickle cell anemia or hereditary spherocytosis) or when antibodies attack and destroy otherwise healthy red blood cells (i.e., transfusion reaction or autoimmune disease). A general term for this type of anemia is hemolytic anemia.
Impaired red blood cell production is a broad category that includes conditions and diseases affecting either the number of red blood cells produced or how they are produced. Red blood cells are produced in the bone marrow in response to the action of a specific hormone (erythropoietin or EPO) made in the kidney. Kidney disease, chronic infection or inflammation, or cancer can decrease the production of EPO or interfere with its activity. Without active EPO, the bone marrow does not produce an adequate number of red blood cells.
Problems inside the bone marrow also interfere with production. Sometimes the marrow stops producing red blood cells that results in a very serious form of anemia called aplastic anemia. This can occur in response to a toxic drug or chemical or infection with certain viruses. Often, however, there is no known reason for the condition (idiopathic aplastic anemia). A decrease in red blood cell production (hypoplasia) is found with malnutrition particularly in the eating disorder called anorexia nervosa. Myelodysplasia refers to a condition where early red blood cells do not develop properly and die before being released into the circulatory system.
Red blood cell production is impaired if there is a problem with the synthesis of deoxyribo nucleic acid (DNA) needed within the cell. This results in an anemia called megaloblastic anemia. Megaloblastic anemia is most often caused by a deficiency of either folate or vitamin B12 (pernicious anemia). Some cases of megaloblastic or aplastic anemia are caused by certain drugs such as chemotherapeutic cancer drugs or exposure to certain chemicals such as benzene.
A problem with the synthesis of hemoglobin can also interfere with normal red blood cell production within the marrow. Because hemoglobin requires iron, a deficiency of iron creates a deficiency of functional hemoglobin. Iron deficiency anemia may result from an insufficient amount of iron in the diet. More often, however, it occurs because either blood loss or increased demand has triggered the marrow to increase production in an effort to replace lost red blood cells. Eventually, the marrow's supply of iron becomes depleted.
Chronic disease is another cause of anemia related to iron. Chronic disease interferes with the normal integration of iron into the red blood cell. Sideroblastic anemia is another type of anemia where iron is not utilized properly. Thalassemia occurs when there is an abnormal production of the proteins needed to make normal hemoglobin and results in anemia.
Some forms of anemia are inherited such as some types of hemolytic anemia and most blood clotting disorders. Disorders of hemoglobin such as sickle cell anemia and thalassemia are also inherited.Risk: Anemia is more common in women than in men, affecting 12.4% of the female population and 6.6% of the male population (Brill). It is present in 10% to 20% of menstruating women and 20% to 60% of pregnant women.
Iron deficiency anemia is the most common type of anemia and is closely associated with menstruating or pregnant women. It is rare in men, but present when associated with gastrointestinal bleeding. Pernicious anemia is also more common in women, particularly blacks. It is less common in other racial or ethnic groups. Folate deficiency is associated with pregnancy, malnutrition, and alcoholism. Sickle cell anemia is the most common hemoglobinopathy and is found primarily in blacks. Thalassemia is associated with individuals of Mediterranean, Southeast Asian, and Middle Eastern or African descent. Incidence and Prevalence: It is estimated that more than 4.5 million Americans have anemia (Brill). |
Source: Medical Disability Advisor
| History: Symptoms depend on the suddenness of onset, severity of the condition, and individual's age and general state of health. Mild anemia and anemia with a gradual onset often have no symptoms. A healthy individual's bone marrow, heart, and lungs can usually compensate for mild anemia. Symptoms typically develop slowly. Sudden onset of anemia such as in severe bleeding (hemorrhage) brings immediate symptoms.
Individuals with general symptoms of anemia report fatigue, weight loss, headache, ringing in the ears (tinnitus), inability to concentrate, heart palpitations, and light-headedness when standing up. Some individuals may have abdominal discomfort, loss of appetite, nausea, diarrhea, or constipation. Individuals with iron deficiency anemia may also complain of a pins-and-needles feeling in the arms or legs and a burning sensation of the tongue. In severe anemia, exercise or exertion may cause breathing difficulties, dizziness, and chest pain. Physical exam: Physical findings may include paleness (pallor) of the skin and creases in the palm of the hand and the mucous membrane (conjunctiva) that lines the eye. The heart rate may increase (tachycardia) and blood pressure may be low when standing up (orthostatic hypotension). If the anemia is severe, a heart murmur may be detected. Breathing rate may also be increased (tachypnea). The liver or spleen may be enlarged. In individuals with pernicious anemia, nerve function may be impaired (peripheral neuritis, neuropathy). Psychiatric symptoms such as depression or confusion may also be present. Individuals with anemia due to chronic disease may have evidence of infection, inflammation, or abnormal tissue growth. Iron deficiency anemia may cause inflammation of the lips (cheilitis) or tongue (glossitis). Fingernails may be fragile or spoon-shaped (koilonychia). Individuals with severe anemia have a decreased urinary output. Tests: A complete blood count (CBC) reveals a low number of red blood cells, low hemoglobin, and/or a low hematocrit. A CBC also reveals the average size of the red blood cells (mean corpuscular volume, or MCV). Physical appearance of the red blood cells can be studied through microscopic examination of a peripheral blood smear. The CBC results plus the information related to the size and appearance of the red blood cells provide clues as to what the cause of anemia may be and what tests to perform next.
A reticulocyte count helps differentiate anemia caused by decreased red blood cell production from that caused by blood loss or increased destruction. Reticulocytes are immature red blood cells, newly released from the bone marrow. A normal number of reticulocytes in the blood indicates that the bone marrow is producing red blood cells. A low number of reticulocytes indicates that the anemia is due to a problem in the bone marrow.
Tests for iron include ferritin, serum iron, and total iron-binding capacity (TIBC). These tests differentiate iron deficiency anemia from other types of anemia involving iron such as sideroblastic anemia and anemia due to chronic disease.
Blood tests for folate and vitamin B12 differentiate between folate deficiency anemia and vitamin B12 deficiency anemia (pernicious anemia). In some cases, a Schilling's test is needed to further study vitamin B12 deficiency. Disorders of hemoglobin (i.e., thalassemia or sickle cell anemia) are confirmed with hemoglobin electrophoresis. This blood test identifies and measures abnormal forms of hemoglobin. Levels of methylmalonic acid and homocysteine can confirm B12 deficiency.
Sometimes a condition is diagnosed by a therapeutic trial. Iron replacement therapy is given for a suspected case of iron deficiency anemia. Vitamin B12 is given to detect vitamin B12 deficiency, and folate for folate deficiency anemia. The diagnosis is made if improvement is seen after therapy.
If the individual's symptoms and initial test results are indicative of a more serious form of anemia, a bone marrow aspiration and biopsy (a sample of bone marrow is removed for microscopic examination) may be necessary to see whether normal red blood cells are being produced at a normal rate. In rare equivocal cases, bone marrow examination may also be necessary to confirm iron deficiency anemia or megaloblastic changes caused by folate or vitamin B12 deficiency.
Other potential underlying causes can be ruled out by further tests such as kidney function tests, blood clotting tests, liver function studies and fecal occult blood.
If acute bleeding is suspected as a cause of the anemia, a search for the site of bleeding is indicated. This may require imaging studies (x-ray, MRI, CT scanning), endoscopy or exploratory surgery. |
Source: Medical Disability Advisor
| The underlying condition or disease causing the anemia should be identified before beginning any treatment except when individual is unstable due to significant blood loss. In this case, a blood transfusion may be required in order to replace lost blood before a diagnosis can be made. However, blood transfusions should be reserved for those who are actively bleeding and are displaying signs of shock or hypoxia.
Treatment is directed toward the underlying cause of the anemia. Iron deficiency anemia due to low iron in the diet or increased demand (such as during pregnancy) is treated with oral iron supplements. Iron deficiency anemia caused by chronic bleeding is treated by finding the cause of the bleeding and treating that condition. Gastrointestinal bleeding is a common cause of iron deficiency anemia and may be treated with a medication such as a histamine (H2) antagonist to stop the bleeding.
Folate deficiency anemia is treated with oral folate supplements. Hormone erythropoietin (EPO) is the hormone that stimulates the bone marrow to produce red blood cells. Injections of EPO are given to replace the EPO deficiency caused by kidney disease. Anemia involving the immune system (immune hemolytic anemia) may be treated with steroids or other immunosuppressive drugs. Some types of anemia require removal of the spleen (splenectomy). More serious forms of anemia may require blood transfusions of red cells, exchange transfusions of whole blood, or a bone marrow transplant from a compatible donor.
Occasionally, ingestion of certain drugs or exposure to certain chemicals can result in anemia. Some examples include sulfinamides, antithyroid drugs, benzene, and radiation. If this is suspected, such drugs or chemicals should be identified and reduced or eliminated.
Treatments are continued until the problem is corrected. Lifelong conditions require lifelong treatment. Most forms of pernicious anemia require lifelong vitamin B12 injections. Individuals with blood clotting disorders will need periodic replacement of the missing clotting factors for the rest of their lives. |
Source: Medical Disability Advisor
| In any anemia the age of the patient and the presence of other comorbid conditions influence outcome.
Outcome of anemia due to blood loss depends on the severity of the loss and response to treatment. If the source of bleeding is identified and corrected, acute anemia due to massive blood loss is successfully treated with transfused blood. Chronic anemia due to a small but chronic blood loss, such as in gastrointestinal bleeding, responds to correction of the bleeding without the need for transfusion.
Anemia caused by deficiencies can usually be corrected by replacement therapy. Iron deficiency anemia typically begins to respond to iron replacement therapy within 1 month and is resolved within 2 months. Megaloblastic anemia caused by a deficiency of either folate or vitamin B12 (pernicious anemia) shows evidence of correction within the bone marrow as quickly as 12 to 24 hours after replacement therapy begins. Blood measurements are back to normal within 2 months. Neuropsychiatric symptoms caused by pernicious anemia may take up to 12 to 18 months to show improvement. The symptoms may not go away completely but with ongoing treatment typically do not progress.
Individuals with severe lifelong anemia such as sickle cell anemia or thalassemia have a shortened life expectancy. Without a bone marrow transplant, severe forms of some anemia are often fatal. |
Source: Medical Disability Advisor
| The gravest complication associated with severe anemia is shock which can result in tissue hypoxia and associated organ damage such as heart attack, respiratory failure, renal failure and possibly death. |
Source: Medical Disability Advisor
| Individuals with mild anemia do not typically require work accommodations or restrictions. Individuals with moderate anemia may experience fatigue, breathlessness, or dizziness with exertion. These individuals require a reduction in the physical requirements of work. This reduction may be temporary or permanent depending on the availability of and response to treatment. Individuals with severe anemia will likely need time off for more intensive treatment or surgery such as bone marrow transplant or splenectomy. |
Source: Medical Disability Advisor
| If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case. Regarding diagnosis:
- Does individual have underlying conditions creating risk of developing anemia such as recent blood loss, malignancy, or renal failure?
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Was diagnosis of anemia confirmed with a complete blood count?
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Were additional serological tests (e.g., total iron binding capacity) performed to determine type of anemia present?
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Was a diagnostic work up performed?
Regarding treatment:
- Has individual received the appropriate intervention to address the underlying cause of the anemia?
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Is individual complying with prescribed treatment?
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Is lifelong treatment necessary?
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Will individual require a splenectomy or bone marrow transplant?
Regarding prognosis:
- Is individual elderly?
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Has underlying cause of the anemia been identified and successfully treated?
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Is success of treatment being monitored by subsequent blood tests? Does individual have access to needed medical care?
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Does individual have an adequate diet? Would individual benefit from nutrition counseling?
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If anemia is related to alcohol abuse, has individual stopped using alcohol?
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Does individual have an underlying condition such as cardiac, pulmonary, kidney, or liver disease that may impact recovery?
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Did individual experience shock associated with severe anemia?
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Source: Medical Disability Advisor
| Brill, John R., and Dennis J. Baumgardner. "Normocytic Anemia." American Academy of Family Physicians. 18 Sep. 2004 <http://www.aafp.org/afp/20001115/2255.html>. |
Source: Medical Disability Advisor
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