Platelet Disorders: Too Few, Too Many, or Platelets That Don't Work

Platelets, also called thrombocytes, are blood cells made in the bone marrow — the spongy tissue inside bones. They are central to clotting: when a blood vessel is injured and bleeds, platelets clump together to plug the hole and stop the bleeding.

Problems come in three kinds.

Too few platelets

A low platelet count is thrombocytopenia. It can lead to bleeding, mild or serious, outside or inside the body. It has many possible causes. Mild cases may need no treatment; more serious ones may need medicines, or blood or platelet transfusions.

Too many platelets

Too many platelets can raise the risk of blood clots.

• Thrombocythemia is a high count with no known cause. It is rare. People without signs or symptoms may not need treatment; others may need medicines or procedures.
• Thrombocytosis is a high count caused by another disease or condition. Its treatment and outlook depend on that cause.

Platelets that don't work properly

Sometimes platelets are present but do not work as they should. In von Willebrand disease, for example, they cannot stick together or attach to the walls of blood vessels, which can cause excessive bleeding. There are several types, and treatment depends on the type.

Sources

• MedlinePlus, U.S. National Library of Medicine, "Platelet Disorders," drawing on the NIH National Heart, Lung, and Blood Institute. https://medlineplus.gov/plateletdisorders.html
• Rewritten in hubnx's own words.