People with neutropenia have an unusually low number of cells called neutrophils. Neutrophils are cells in your immune system that attack bacteria and other organisms when they invade your body.
Neutrophils are a type of white blood cell. Your bone marrow creates these cells. They then travel in your bloodstream and move to areas of infection. They release chemicals to kill invading microorganisms.
A healthy person usually has a platelet count of 150,000 to 400,000. You have thrombocytopenia if your number falls under 150,000.
If you're wondering what the long name means, here's how it breaks down: "thrombocytes" are your platelets and "penia" means you don't have enough of something. Put those terms together, and you get "thrombocytopenia."
Your doctor may tell you that you have a form of the condition called idiopathic thrombocytopenic purpura (ITP). "Idiopathic" means the cause isn't known. "Purpura" refers to bruising, which is one of the symptoms.
Although doctors don't know what causes ITP, they know that it happens when your immune system -- your body's defense against disease -- doesn't work right. Your antibodies, which are supposed to attack infections, instead mistakenly destroy your blood platelets.
Thrombocytopenia can run in families, but you can also get it from some drugs and many medical conditions. For instance, your body might make fewer platelets if you have:
You could also get thrombocytopenia if you're taking chemotherapy drugs or you're getting radiation treatment on your bone marrow. Drinking a lot of alcohol can also bring on the condition.
Thrombocytopenia can also happen if your spleen is enlarged, which can trap platelets so they won't move through your body.
In other cases, your body just uses too many platelets, leaving you without enough of them. That can happen if you have an autoimmune disease, like rheumatoid arthritis or lupus. The same is true if you have thrombotic thrombocytopenic purpura (TTP), which uses a lot of platelets to make small blood clots throughout your body.
Your blood platelets can also be destroyed because of: