Definitions & Types of Anemia and its Treatments

 Definitions & types of anemia and its treatments

Definition    Return to 

Anemia is a lower than normal number of red blood cells (erythrocytes) in the blood, usually measured by a decrease in the amount of hemoglobin. Hemoglobin is the red pigment in red blood cells that transports oxygen.

 

There are many types and potential causes of anemia. For information about a specific type of anemia, see one of the following articles:

• Anemia - B12 deficiency

• Anemia - folate deficiency

• Anemia - iron deficiency

• Anemia due to chronic disease

• Hemolytic anemia

• Hemolytic anemia - G-6-PD deficiency

• Idiopathic aplastic anemia

• Idiopathic autoimmune hemolytic anemia

• Immune hemolytic anemia

• Immune hemolytic anemia - drug-induced

• Megaloblastic anemia

• Pernicious anemia

• Secondary aplastic anemia

• Sickle cell anemia

 

 

Anemia - B12 deficiency     

Alternative names    Return to top

 

 Macrocytic anemia

 

Definition 

  

Anemia is a drop in the number of red blood cells. This can be caused by a lack of vitamin B12

.

Causes, incidence, and risk factors    

 

Vitamin B12 is essential for normal nervous system function and blood cell production. The main sources of vitamin B12 include meat, eggs, and dairy products. For vitamin B12 to be absorbed by the body, it must bind to intrinsic factor, a protein secreted by cells in the stomach.

Causes of vitamin B12 deficiency include:

• A diet low in vitamin B12 (for example, a strict vegetarian diet that excludes all meat, fish, dairy products, and eggs)

• Chronic alcoholism

• Abdominal or intestinal surgery that affects intrinsic factor production or absorption

• Crohn's disease

• Intestinal malabsorption disorders

• Fish tape worm

• Pernicious anemia, which is caused by a lack of intrinsic factor

The risk factors are related to the causes.

 

Symptoms   

 

• Loss of appetite

• Diarrhea

• Numbness and tingling of hands and feet

• Paleness

• Shortness of breath

• Fatigue

• Weakness

• Sore mouth and tongue

• Confusion or change in mental status in severe or advanced cases

Signs and tests    

 

A physical evaluation of the patient's neurological signs may show depressed deep tendon reflexes, decreased position sense, decreased vibration sense, or positive Babinski reflex. Other signs and tests include the following:

• CBC results show low hematocrit with an elevated MCV

• Bone marrow examination

• Elevated LDH

• Below-normal vitamin B12 level

• Schilling test (to determine where the deficiency in B12 absorption lies).

Treatment    

 

Treatment depends on the cause of the anemia:

• Pernicious anemia requires lifelong therapy with vitamin B12 injections.

• Anemia caused by a lack of vitamin B12 can be corrected by vitamin pills combined with a more balanced diet. It may be treated initially with vitamin B12 injections.

• Anemia caused by malabsorption is treated with vitamin B12 injections until the condition improves.

Expectations (prognosis)    Return to top

Treatment for this form of anemia is usually effective.

Complications    

• The signs and symptoms related to the central nervous system may be irreversible if treatment is not begun within 6 months of when these symptoms begin.

• Vitamin B12 affects epithelial cells (cells that form the outer surface of the body and line inner passageways). Therefore, a lack of B12 may cause a false-positive Pap smear.

Calling your health care provider    

 

Call your health care provider if you have any of the symptoms of anemia.

 

Prevention    

Anemia caused by a lack of vitamin B12 can be prevented through a well-balanced diet. B12 injections can prevent anemia after surgeries known to cause vitamin B12 deficiency. Early diagnosis and prompt treatment can limit the severity of this anemia as well as the neurologic complications.

 

Megaloblastic anemia - view of red blood cells 

 

 

This picture shows large, dense, oversized, red blood cells (RBCs) that are seen in megaloblastic anemia. Megaloblastic anemia can occur when there is a deficiency of vitamin B-12.