What's Platelets in Blood?

Platelets, or thrombocytes, are small, colorless cell fragments in our blood that form clots and stop or prevent bleeding. Platelets are made in our bone marrow, the sponge-like tissue inside our bones. Bone marrow contains stem cells that develop into red blood cells, white blood cells, and platelets.

What is a normal platelet count?

A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. Having more than 450,000 platelets is a condition called thrombocytosis; having less than 150,000 is known as thrombocytopenia. You get your platelet number from a routine blood test called a complete blood count (CBC).

What does it mean when your platelet count is low?

When you don't have enough platelets in your blood, your body can't form clots. A low platelet count may also be called thrombocytopenia. This condition can range from mild to severe, depending on its underlying cause. For some, the symptoms can include severe bleeding and are possibly fatal if they're not treated.