Platelets are the smallest type of blood cell; platelets regulate the blood's ability to clot. Platelets are irregularly shaped, sticky cells that clump together at a wound site to stop bleeding. The normal platelet range is between 140,000 and 440,000 platelets per microliter, according to the Merck Manual. Both too many platelets and too few can cause symptoms; symptoms can also be caused by drugs or diseases that inhibit platelet actions, even when platelet numbers are normal.
Low Platelet Count Symptoms
The most common symptoms of low platelets are easy bruising and bleeding; symptoms don't usually occur until platelets drop below 50,000 per microliter. In severe low counts, or thrombocytopenia, pinpoint bleeding into the skin called petechiae appears on the skin. Menstrual periods may be unusually heavy, and blood may be found in the urine or bowel movements. Bowel movements that appear black can contain large amounts of blood. Nosebleeds and bleeding gums may follow activities as simple as brushing your teeth or blowing your nose. When platelet counts drop to 10,000 to 20,000, Merck says spontaneous bleeding internally or into the brain can occur.
Two rare types of thrombocytopenia can cause different symptoms. Thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome are low platelet disorders where the drop in platelets is caused by multiple clots forming all over the body. Symptoms of low platelets related to these disorders may include abdominal pain, headache, seizures, confusion and heart arrhythmias. Hemolytic uremic syndrome causes severe kidney damage; urine may be bloody.
Elevated Platelet Count Symptoms
Symptoms of too high platelet counts, or thrombocythemia, are caused by clots forming in the circulatory system that block blood flow. Hands and feet may be cold and tingling; vision changes, headaches, chest pain and light-headedness can occur, Merck says. Nosebleeds, gums that bleed easily and bleeding in the gastrointestinal tract are seen when platelet counts are too high as well as too low.
Platelet Dysfunction Symptoms
Some symptoms of platelet problems are caused by diseases and medications that interfere with platelet function. Symptoms of platelet dysfunction include easy bruising and prolonged bleeding from minor injuries; normal daily activities can result in unexplained bruising that you can't account for. Aspirin is one drug known for its anti-clotting effects, the University of Oklahoma Health Science Center states. Von Willebrand disease, an inherited disease, interferes with a protein that helps platelets stick together.
