Types of Anemia

Anemia is caused by either a decrease in production of red blood cells or hemoglobin, or an increase in loss due to bleeding or destruction of red blood cells.

Updated: January 2, 2018

Anemia is a medical condition in which the red blood cell count or hemoglobin is less than normal. Hemoglobin is a main part of red blood cells which binds oxygen and carry it to the tissues.
If your red blood cell count is low or your hemoglobin is low, the cells in your body will not get enough oxygen. Anemia is caused by either a decrease in production of red blood cells or hemoglobin, or an increase in loss due to bleeding or destruction of red blood cells.
Anemia is usually defined as hemoglobin level of less than 13.5 gram/100 ml in men and less than 12.0 gram/100 ml in women.

Types of Anemia:

There are several types of anemia because of number of medical conditions. Different types of anemia are:

Iron deficiency anemia:

Anemia that is due to low iron levels is called iron deficiency anemia. Iron deficiency is a very common cause of anemia. Your bone marrow needs iron to make hemoglobin. Your body can not produce enough hemoglobin for red blood cells without adequate iron which is major component of hemoglobin and essential for its proper function.
The main cause of low iron level in the body due to chronic blood loss for any reason. To compensate for the ongoing loss of iron it reduces the stored iron in your body. Because of the loss of blood each month through normal menstruation, young women are likely to have low grade iron deficiency anemia. Recurring or small ongoing bleeding, such as colon cancer or from stomach ulcers can be another common reason for iron deficiency anemia.
Stomach ulcer bleeding may be induced by medications. Digestive conditions such as Crohn's disease or surgical removal of part of the stomach or small intestine can lead to iron deficiency anemia. Most often due to a diet lacking iron, iron deficiency anemia occurs in infants and young children.
This type of anemia occurs in many pregnant women without iron supplementation.

Sickle cell anemia:

Sickle cell anemia is an inherited disorder. Because of a genetic defect the red blood cells become crescent-shaped. The organ of the body could not get oxygen as they break down rapidly causing anemia. The crescent-shaped red blood cells can also get stuck in tiny blood vessels, causing pain.

Aplastic anemia:

Aplastic anemia is very rare and is a life-threatening form of complete bone marrow failure. As a result there is a reduction in red blood cells, white blood cells as well as platelets in your blood. The symptoms of this anemia are similar to the symptoms of all anemia as well as recurrent infections and abnormal bleeding.
Causes of aplastic anemia include:

cancer treatments such as radiation therapy or chemotherapy
chronic exposure to toxic chemicals
infections such as certain viral infections
medications, for examples, chloramhenicol, carbamazepine, and phenytoin
myelodysplastic syndromes
genetic abnormalities

Vitamin-deficiency anemia:

This may occur when vitamin B12 and folate are deficient which are two essential vitamins to make red blood cells. Deficiency of vitamin B12 or folate or both can lead to megaloblastic anemia. Poor vitamin B12 absorption caused by conditions such as Crohn's disease, an intestinal parasite infection, surgical removal of part of the stomach or intestine, or infection with HIV can lead to pernicious anemia. Eating little or no meat may cause a lack of vitamin B12, while overcooking or eating too few vegetables may cause a folate deficiency causing dietary deficiency. Pregnancy, certain medications, alcohol abuse, intestinal diseases such as tropical sprue and celiac disease can also cause vitamin deficiency.
Sufficient folic acid can help prevent the fetus from developing neural tube defects such as spina bifida during early pregnancy.

Anemia associated with other conditions:

Usually this type of anemia occurs when there are too few hormones necessary for red blood cell production. Conditions causing this type of anemia include: