Definition: a condition in which the number of red blood cells and hemoglobin is reduced, reducing the capacity to carry oxygen

Causes:

There are many types of anemia, but the most common include iron deficiency anemia, due to decreased ingestion or utilization of iron or excessive bleeding causing iron loss; pernicious anemia which is due to malabsorption of vitamin B12 due to absence in the diet or decreased secretion of intrinsic factor from the stomach which is necessary for absorbing B12; and various anemias due to blood diseases or genetic disorders such as sickle cell anemia.

Signs and Symptoms:

Fatigue, weakness, and inability to concentrate are the most common symptoms of iron deficiency anemia. Sometimes mood changes and a rapid heart beat are present. The symptoms of iron deficiency can occur before anemia develops, however. A blood test is the only way to definitively test for anemia.

Pernicious anemia is characterized by the above symptoms. At an advanced state, neurological symptoms develop, including numbness or tingling in the peripheral nerves and problems with balance. The patient may also appear pale. 

Treatment: 

Medically, depending on the type of anemia, a person may be prescribed iron or B12 injections or supplements. With both type of anemias, it is important to identify the cause of the anemia, whether it be chronic bleeding in iron deficiency anemia or simply decreased ingestion of iron, or gastrointestinal causes for B12 deficiency. Treatment of the underlying cause will result in the best outcome. Chronic alcoholism can also lead to deficiency of B12 and must be addressed.

Alternative treatment includes the above supplementation, along with digestive enzymes, including hydrochloric acid, for better utilization of nutrients in the food. Strict vegetarians are at risk for B12 deficiency anemia since B12 almost exclusively comes from animal sources. Eating good quality meat or eggs will help with both types of anemia.