Key Points

• Thrombocytopenia is a condition in which your blood has a low number of blood cell fragments called platelets. Platelets travel through your blood vessels and stick together (clot) to stop any bleeding that could happen if a blood vessel is damaged.
• When the blood has a low number of platelets, mild to serious bleeding can occur. This bleeding can happen inside the body (internal bleeding) or on the skin.
• A normal platelet count is 150,000 to 450,000 platelets per microliter of blood. A count of less than 150,000 platelets per microliter is lower than normal. However, the risk for serious bleeding doesn't occur until the count becomes very low—less than 10,000 or 20,000 platelets per microliter. Milder bleeding sometimes occurs when the count is less than 50,000 platelets per microliter.
• In general, a low platelet count develops for one or more of these reasons:
  • The body's bone marrow doesn't make enough platelets.
  • The bone marrow makes enough platelets, but the body destroys them or uses them up.
  • The spleen holds on to too many platelets. The spleen is an organ that helps your body fight infection and remove unwanted cell material.
• Mild to serious bleeding causes the main signs and symptoms of thrombocytopenia. Signs and symptoms can appear suddenly or over time. Mild thrombocytopenia often has no signs or symptoms.
• Your doctor will diagnose thrombocytopenia based on your medical history, a physical exam, and tests results.
• Treatment for thrombocytopenia depends on its cause and how severe the condition is. Thrombocytopenia often is improved by treating its underlying cause. For severe cases, medicines, blood or platelet transfusions, or splenectomy (removal of the spleen) may be needed.
• Most cases of thrombocytopenia can't be prevented. However, you can take steps to avoid its complications. Avoid drinking alcohol. Avoid medicines that have decreased your platelet count in the past. Be aware of medicines that may affect your platelets and raise your risk for bleeding. Talk with your doctor about getting vaccinated for viruses that can affect your platelets.
• If you have thrombocytopenia, watch for signs and symptoms of bleeding. Report these signs and symptoms to your doctor right away. Watch what medicines you take, avoid injury, and contact your doctor if you have a fever or other signs and symptoms of an infection.
• Thrombocytopenia can be life threatening, particularly if the bleeding is severe or occurs in the brain. However, the overall outlook is good, especially if the cause of the low platelet count is found and treated.