ரத்தப் பரிசோதனை- நோய்களை கணிக்க ரத்தப் பரிசோதனை ஏன் செய்யப்படுகிறது? Complete blood count test

A complete blood count (CBC) - How to?

A complete blood count (CBC) gives important information about the kinds and numbers of cells in the blood, especially red blood cells , white blood cells , and platelets . 
A CBC helps to diagnose conditions, such as anemia , infection, and many other disorders.

A CBC test usually includes:

Red blood cell (RBC) count

Red blood cells carry oxygen from the lungs to the rest of the body. They also carry carbon dioxide back to the lungs so it can be exhaled. If the RBC count is low (anemia), the body may not be getting the oxygen it needs. If the count is too high (a condition called polycythemia), 
there is a chance that the red blood cells will clump together and block tiny blood vessels (capillaries). 
This also makes it hard for your red blood cells to carry oxygen.

Hematocrit 

This test measures the amount of space (volume) red blood cells take up in the blood. The value is given as a percentage of red blood cells in a volume of blood. For example, a hematocrit of 38 means that 38% of the blood's volume is made of red blood cells. Hematocrit and hemoglobin values are the two major tests that show if anemia or polycythemia is present.

Hemoglobin (Hgb)

The hemoglobin molecule fills up the red blood cells. It carries oxygen and gives the blood cell its red color. The hemoglobin test measures the amount of hemoglobin in blood and is a good measure of the blood's ability to carry oxygen throughout the body.

White blood cell count

White blood cells protect the body against infection. If an infection develops, white blood cells attack and destroy the bacteria, virus, or other organism causing it. White blood cells are bigger than red blood cells but fewer in number. When a person has a bacterial infection, the number of white cells rises very quickly. The number of white blood cells is sometimes used to find an infection or to see how the body 
is dealing with cancer treatment.

White blood cell types  

The major types of white blood cells are neutrophils , lymphocytes, monocytes, eosinophils, and basophils. Immature neutrophils, called band neutrophils, are also part of this test. Each type of cell plays a different role in protecting the body. The numbers of each one of these types of white blood cells give important information about the immune system . Too many or too few of the 
different types of white blood cells can help find an infection, an allergic or toxic reaction to medicines or chemicals, and many conditions,such as leukemia .

Platelet (thrombocyte) count

Platelets (thrombocytes) are the smallest type of blood cell. They are important in blood clotting. When bleeding occurs, the platelets swell, clump together, and form a sticky plug that helps stop the bleeding. If there are too few platelets, uncontrolled bleeding may be a problem. If there are too many platelets, there is a chance of a blood clot forming in a blood vessel. Also, platelets may be involved in hardening of the arteries .