When your platelets are high, it means you have a condition called thrombocytosis, where your blood has more platelets than normal. Platelets are tiny blood cells that help your body form clots to stop bleeding. A normal platelet count ranges roughly from 150,000 to 450,000 platelets per microliter of blood. Having more than 450,000 platelets per microliter is considered high.

There are two main types of high platelet counts:

• Reactive or secondary thrombocytosis: This is more common and happens as a reaction to another condition such as infection, inflammation, cancer, blood loss, iron deficiency, surgery, or certain medications. This type is often temporary.

• Essential or primary thrombocythemia: This is a bone marrow disorder where too many platelets are produced, often due to genetic mutations. It poses a greater risk for clotting or bleeding complications.

Many people with high platelets do not have symptoms, but when present, symptoms are often related to abnormal clotting or bleeding. These may include headaches, confusion, chest pain, shortness of breath, weakness, burning pain in hands or feet, nosebleeds, bruising, bleeding from the mouth or gums, or bloody stool.

High platelet counts can increase the risk of developing blood clots, which can lead to serious health issues like stroke or heart attack, or, less commonly, cause bleeding problems if the platelet function is abnormal.

In summary, a high platelet count means the body is producing too many platelets, often in response to another condition or due to a bone marrow disorder, and it may lead to symptoms related to clotting or bleeding risks. Evaluation by a healthcare provider is important to determine the cause and appropriate management.