Friday, October 15, 2010

Classification of Anemia

ANEMIA
By Melanie Huff

     There are over 400 types of Anemia. This condition will affect over half of the world’s population at some point during their lives. Anemia is defined as a reduction in the number or volume of circulating red blood cells or an alteration in hemoglobin. Technically Anemia is not a disease but only a symptom of numerous other disorders. The origin of Anemia is classified either as nutritional or non-nutritional.  

Classification of Anemia 
Nutritional Anemia is mainly caused by a lack of iron, vitamin B 12, or folic acid. Also a deficiency in the amount of vitamins such as B2, B6, C, A, D, E, and K can lead to nutritional anemia. Zinc, copper, calcium, and proteins are other causes of anemia. A lack of certain enzymes can also cause anemia. Often anemia is associated with scurvy which indicates low levels of folate and iron. Discoveries have been made that show vitamin C increases the absorption of iron but studies show that it may also increase the absorption of folate


                     

            
                                                                          

        Vitamin B 12                                            Folic Acid


     Non-nutritional anemia is classified into two types- etiology and morphology. Etiology studies the causes of erythrocyte (red blood cell) and/or hemoglobin reduction. On the other hand, morphology studies the changes in the erythrocytes themselves such as – color, shape, and size. These changes are described in the following table:



Cell size:
Normocytes- Normal size of cells
Microcytes- Smaller than normal size cells
Macrocytes- Bigger than normal size cells
Anisocytes- Various sizes
Cell shape:
Poikilocytes- Irregularly shaped cells
Spherocytes- Globular shaped cells
Drepanocytes- Sickle shaped cells
Cell Color: Actually refers to the amount of hemoglobin which determines the color of cells
Normochromic- Normal amounts of hemoglobin
Hyperchromic- Unusually high concentration of hemoglobin
Hypochromic- Unusually low levels of hemoglobin

These changes produce several other categories of anemia including- Macrocytic-normochromic anemias, Microcytic-hypochromic anemias, and Normocytic-normochromic anemias.


Macrocytic-normochromic Anemia
     This condition is also known as megalobastic anemia. In this type of anemia the erythrocytes are abnormally large (macrocytic) and abnormally shaped but there are normal amounts of hemoglobin (normochromic). Erythrocytes develop from stem cells in the bone marrow. In people with this type of anemia their stem cells are abnormally large which produces unusually large erythrocytes. Also these large erythrocytes have a small nucleus compared to the size of the cell. The chromatin in the nucleus does not clump properly which means that the DNA cannot effectively replicate itself. This causes ineffective erythropoiesis which in the formation of red blood cells. The defective DNA synthesis is caused by a deficiency in either vitamin B 12 or folate. This deficiency causes premature cell death which results in a reduced number of mature erythrocytes.
                 
       
Macrocytic-normochromic Anemia               Healthy Red Blood Cell

Microcytic-hypochromic Anemia
     In this type of anemia the erythrocytes are abnormally small and the amount of hemoglobin is reduced. Hypochromia can also occur in cells that are normal in size. This condition results from irregular iron metabolism, porphryin, and globin synthesis.
                    
     

 Microcytic-hypochromic Anemia                             Healthy Red Blood Cells


Normocytic-normochromic Anemia
     In this condition both the size of the erythrocytes are normal and the hemoglobin content also normal. The problem is that there is not a sufficient number of erythrocytes. There is no specific cause of this type of anemia but it is also very rare. This class of anemia is also very diverse. There are five distinct conditions in this type of anemia.
                 
   
      

Normocytic-normochromic Anemia     -Healthy Red Blood Cells

Aplasitc anemia
Occurs when there is damage to the bone marrow which results in a slowing or stopping of the production of erythrocytes
Posthemorrhagic anemia
Caused from an abnormal loss of blood
Hemolytic anemia
The destruction of mature erythrocytes in circulation
Anemia of chronic disease
Caused by an increase in the demand for new erythrocytes
Sickle cell anemia
Dysfunction of hemoglobin synthesis resulting in abnormally shaped erythrocytes


SYMPTOMS
     Symptoms of anemia often go undetected. Several of the symptoms include loss of appetite, constipation, headaches, noises in the ears, irritability, difficulty in concentration and memory. As anemia progresses other symptoms become apparent such as: weakness, fatigue, coldness of the extremities, depression, dizziness, all over pallor, pale and brittle nails, pale lips and eyelids, pallor in the palms of the hands, soreness of the mouth, restless leg syndrome, and a cessation in menstruation or in libido.

ORGANS AND SYSTEMS EFFECTED
When anemia is severe or comes on very fast, blood vessels constrict flow so that the most important organs get the blood. This affects several different organs and systems in the body such as:
Kidneys
Decreased blood flow is sensed by the kidneys which causes the renal glands to releases renin which stimulates salt and water retention in the kidneys
Hair
Decreased oxygen causes the hair to thin and go grey
Nervous System
Myelin degeneration with loss of nerve fibers
Gastrointestinal tract
Decreased oxygen supply produces abdominal pain, nausea, and vomiting
Skin
Decreased oxygen results in impaired hearing and loss elasticity
Other areas
Skin, mucous membrane, lips, nailbeds, and conjunctiva become pale


 DIAGNOSIS
To test for anemia doctors do a complete blood count test, also known as a CBC. Most of the time, the blood sample is collected from a finger prick. This test checks for the amount of hematocrit which is the percentage of the blood that is red blood cells or erythrocytes. It also measures the amount of hemoglobin in the blood.

TREATMENT
Treatment varies depending on the type of anemia. Nutritional anemia is much easier to treat. For an iron deficiency anemia doctors most often prescribe one of two things- either a diet rich in iron containing foods such as liver, seafood, dried fruits, lima beans, whole grains, and green leafy vegetables or iron pills. Another type of nutritional anemia is a vitamin B 12 deficiency. To treat this type of anemia the patient must receive life-long monthly injections of B 12. For a folate deficiency most often a dietary change is needed. Foods rich in folate include meat, poultry, cheese, milk, eggs, liver, green leafy vegetables, raw fruits, lima or kidney beans, and yeast. Sometimes in severe cases folic acid injections may be required. Treatments for other types of anemia include oxygen, fluids, fresh frozen plasma, platelet replacement, and vasopressors.

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1 comment:

  1. post various other types of anemias,too.otherwise the presentation is good,but needs to be elaborated.

    ReplyDelete