What are platelets?
Platelets are cells made in the bone marrow and then released into the blood. Platelets stick together to help form blood clots. Blood clots help stop the bleeding when you have a cut or wound.
How does the body keep the right number of platelets in the blood?
The body needs a certain number of platelets in the blood to help stop bleeding from cuts and wounds on the skin. Platelets also work to prevent bruising (bleeding under the skin).
Platelets are made in the bone marrow. The body uses a hormone, called thrombopoietin (THROM-bo-po-EE-tin) or TPO, that is made in the liver to signal special cells in the bone marrow. The signal tells those cells to make new platelets, which are then released into the blood.
The spleen stores some of these platelets in case the body needs them. Old platelets are destroyed by the spleen. The bone marrow makes new platelets to replace the old ones. This normal process keeps the right number of platelets in the blood.
What happens when your platelet count is too low or goes up and down?
If your platelet count is low:
- Your body cannot respond as it should to injury which may result in bruising or bleeding that is hard to stop
- You may feel tired
If your platelet count goes up and down:
- You may worry and feel anxious about whether you have enough platelets on any given day
Parts of the body used to make platelets
Why does ITP lower the number of platelets?
The immune system normally finds and destroys the foreign substances that may make you sick. It uses markers, called antibodies, to tell the body which cells to destroy. In ITP the immune system thinks that platelets are cells that will hurt the body. These platelets are marked by antibodies and destroyed by the immune system. ITP may also cause the body not to make enough platelets. Also, with ITP your body may not produce enough platelets to make up for the ones your immune system has destroyed.
