Platelet disorders are medical conditions that affect the number or function of platelets, which are small cell fragments in the blood essential for clotting. These disorders can lead to excessive bleeding or unusual clotting, depending on whether there are too few platelets (thrombocytopenia) or if the platelets do not work properly (functional platelet disorders). Common types of platelet disorders include idiopathic thrombocytopenic purpura (ITP), where the immune system mistakenly destroys platelets, and thrombotic thrombocytopenic purpura (TTP), which involves small blood clots forming throughout the body. Diagnosis typically involves blood tests to assess platelet count and function.