Anemia is a common problem worldwide, affecting as much as one-third of the world‘s population. It can be caused by decreased production or increased destruction of erythrocytes, or by blood loss. The causes of anemia worldwide will reflect local patterns of disease. In the UK the most common cause of anemia is iron deficiency. In hospitals, however, anemia secondary to chronic disease predominate. In some developing countries, human immunodeficiency virus (HIV), tuberculosis (TB), hookworm and malaria are the most important causes.
Symptoms vary depending on the cause:
- Anorexia and bowel disturbance
Anemias may be classified either morphologically or by cause. Anemias are micro-, normo- or macrocytic, depending on the mean cell volume (MCV). The mean
amount of hemoglobin in each erythrocyte (MCH) is also measured. If the MCH is low, the anemia is hypochromic. All of this information is usually given in a full blood count result.
Iron deficiency is the most common cause of anemia worldwide. It occurs most frequently in women of reproductive age. If iron utilization outweighs intake, stores eventually become depleted resulting in anemia. Causes of iron-deficiency anemia include:
- Decreased iron intake, e.g. due to poor diet
- Increased iron requirement, e.g. during growth, pregnancy and lactation
- Chronic blood loss, e.g. heavy menstrual bleeding or gastrointestinal (GI) blood loss
- Decreased iron absorption, e.g. after gastrectomy
Clinical management involves identifying and treating the underlying cause of the iron deficiency, as well as supplementation. Oral administration of iron is in the form of ferrous sulphate tablets. This must be continued for 4–6 months to replenish iron stores. Common side effects of oral iron supplementation include constipation, diarrhea and dark feces. Parenteral iron is used if the patient has malabsorption or cannot tolerate oral preparations.