Anemia
Overview of Anemia
Anemia affects millions of people worldwide. The National Center for Health Statistics estimated that 3.4 million Americans are living with anemia.1 Nevertheless the actual anemic individuals may be even greater as anemia is often under-diagnosed and under-treated. Anemia is one of the most prevalent public health problems in most of the developing countries and has serious consequences on national development. Iron deficiency anemia (IDA) is the most common nutritional deficiency and is one of the leading risk factors for disability and death worldwide, affecting an estimated two billion people.2
Although anemia is usually a consequence of many diseases including chronic inflammatory, infectious or neoplastic disorders, it may also occur from the treatment of the disease itself. Anemia may affect school children, adolescents, elderly and reproductive-age women. It has serious negative consequences including increased mortality in women and children, reduced capacity to learn and decreased productivity in all individuals. Anemia in the elderly is linked to an increase in morbidity and mortality.3 Pregnant women often show IDA as a consequence of increased plasma volume during pregnancy. Gynecological anemia is often caused by hypermenorrhea (increased menstrual bleeding).4
Treatment should be directed at the cause of the anemia. This article will discuss in detail regarding the different classes and types of anemia, the causes, the risk factors and the diagnosis and management strategies for anemia of various origin.
Classifications of Anemia
Anemia can be classified by cytometric methods, based on the morphology of red blood cells (RBCs), erythrokinetic schemes (the rates of RBCs production and destruction) and biochemical or molecular methods
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Causes of Anemia
Significant causes of anemia include nutritional deficiencies other than iron deficiency (folic acid and vitamin B12 deficiencies), genetic conditions (thalassemia, sickle cell anemia (SCA) or hemoglobinopathies), factors related
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Risk Factors of Anemia
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Symptoms of Anemia
Symptoms of anemia vary depending on the severity of the condition. Symptoms can sometimes be vague and be detected only during a clinical examination and investigation. In general, the symptoms and signs
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Diagnosis of Anemia
Anemia is diagnosed based on the patient's symptoms and from various laboratory tests.9 As anemia is best defined in relation to hemoglobin (Hb) and hematocrit (HCT) levels below the normal reference range, the first test used
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Treatment and Prevention of Anemia
Treatment is directed at the cause of the anemia. Severe anemia is life-threatening and can be treated in the hospital with blood transfusions. The treatment of different types of anemia will be discussed in detail in their
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Iron Deficiency Anemia
Iron deficiency anemia is the most common nutritional deficiency worldwide involving individuals of all ages. Although the etiology is multifaceted, IDA generally results when the body’s iron demands are not adequately met
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Vitamin Deficiency Anemia
Folate, vitamin B6, vitamin B12 and vitamin C are the vitamins needed for a body to produce healthy RBCs. Deficiency in one or more of these vitamins may cause anemia. Among these, the commonest type is megaloblastic anemia (MA) caused by deficiencies in vitamin B12 and folic acid. Dietary vitamin B12 deficiency usually results from inadequate absorption but deficiency can develop in vegans who do not take vitamin supplements. Other than MA, vitamin B12 deficiency also causes damage to the white matter of the spinal cord and brain, and peripheral neuropathy.
This type of anemia is characterized by many large immature and dysfunctional RBCs (megaloblasts) in the bone marrow, and also by hypersegmented or multisegmented neutrophils. Symptoms of MA develop slowly and are similar to symptoms produced by other types of anemia. Neurologic symptoms such as mild-to-moderate weakness and neural pain may develop independently from and often without hematologic abnormalities.
Other than inadequate nutritional intake, vitamin B12 deficiency may also result from lack of intrinsic factor in gastric (stomach) secretions, which is necessary for gastrointestinal absorption of vitamin B12. This type of anemia in which a lack of intrinsic factor occurs is called pernicious anemia. Other types of MA may be associated with type 1 diabetes, thyroid disease, leukemia and a family history of the disease.
Diagnosis and Treatment
In addition to a complete medical history and physical examination, diagnostic procedures for MA may include blood tests such as CBC, serum B
12, serum folate, bone marrow examination and additional investigation such as the Schilling test. The Schilling test is useful in diagnosing intrinsic factor deficiency, as in classic pernicious anemia.
The treatment of MA consists of replacement of the deficient vitamin. Oral vitamin B12 in the dosage of 1000–2000 μg (1–2 mg) can be given on daily basis to patients who do not have severe deficiency or neurologic manifestations. For more severe deficiency, vitamin B12 is commonly administered by injection. Initially intramuscular injection of vitamin B12 1 mg is usually given daily or weekly for several weeks until the blood levels of vitamin B12 return to normal. Subsequently, the injections are given once a month. Folic acid can be taken as, one tablet daily in the dosage of 0.5–1 mg. Vitamin B12 treatment must be continued lifelong unless the causative mechanism for the deficiency is corrected.
Anemia of Chronic Disease
Anemia of chronic disease, a mild-to-moderate anemia seen with many infections and inflammatory disorders, is the second mostprevalent type after anemia caused by iron deficiency. Anemia of chronic disease occurs inpatients
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Anemia of chronic disease...
Other Types of Anemia
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Anemia in Pregnancy
The prevalence of anemia in pregnant women has remained high worldwide despite the fact that routine iron supplementation during pregnancy has been universally recommended to prevent maternal anemia, especially
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- Anemia is one of the most prevalent public health problems.
- Anemia is often underdiagnosed and undertreated.
- Iron deficiency is the most prevalent nutritional disorder worldwide, especially in developing countries.
- Iron deficiency is the most common type of anemia followed by ACD.
- Some types of anemia are due to inherited or genetic defects.
- Different types of anemia are characterized by discrete hematologic patterns.
- The consequences of anemia are many and serious, affecting not only individuals’ health but also the development of societies and countries.
- There are many different treatments for anemia and the treatment depends on severity and the cause.
- Iron supplementation and food fortification are the most cost-effective means of addressing IDA.
- Anemia in pregnancy is very common but severe anemia in pregnancy may have adverse effects for the newborn and should be treated or prevented early in pregnancy.
Written by: Healthplus24 team
Date last updated: February 09, 2010