Reading a CBC, Platelets / PLT

Platelets are also called "thrombocytes" and are often counted by machines, but can also be counted on hemocytometers or during manual diffs and then they can be calculated as follows:

(Platelets/100 leukocytes) X (WBC count/mcg) = Platelets/mcg

Here's what a thrombocyte looks like:

Platelets are essential in the body's ability to form a clot when bleeding occurs.

Increased platelets or "thrombocytosis" can be caused by:-Excitement: epinephrine release can cause the number of platelets to increase temporarily.
-Infections
-Inflammation
-Acute or chronic blood loss: the platelets are lost along with the blood.
-Drugs: such as steroids.
-Hyperadrenocorticism: overactive adrenal glands.
-Splenectomy: the spleen is responsible for destroying old platelets which may remain in circulation if the spleen has been removed or is not functioning properly.
-Cancer
-Discontinuation of chemotherapy.

Decreased platelets or "thrombocytopenia" can be caused by:-Decreased production: of platelets by the bone marrow.
-Clotting: the platelets may be used up due to extensive clotting.
-Immune disorder: the immune system may attack its own platelets.
-Sequestration: removal of platelets from the general circulation, possibly due to splenomegaly (an enlarged spleen).