The two main types of platelet disorders can be: those which are involving the quantity of platelets in blood and those which are relating to the functioning of the platelets. Patients having platelet disorders may be have abnormal functioning of platelets or maybe the numbers of platelets are very high or low. The disorders can be inherited or not and they can be relating because of abnormal immune system. It is really important during diagnosis to know whether the platelet disorder is inherited or is it because of abnormal immune system.

Disorders of platelets which are relating to the numbers can be caused by over or underproduction of platelets in the bone marrow and maybe they have abnormal rates of destruction and sequestration in the body. A complete blood count or CBC test is often required to diagnose these types of platelet disorders. The blood is drawn and tested in laboratory with various procedures to mark the results.

Platelet disorders which are relating to functioning are often normal in number count but they are forming abnormal functions. Examples of functioning platelet disorders are Willebrand's disease and Bernard-Soulier Disease. These conditions are usually genetic but they can be treated.

If a patient is diagnosed to have a platelet disorder, he or she will be referred to a hematologist. Hematologist is an expert of blood disorders and he can further take tests to diagnose exact condition and can treat with the most appropriate option. Some genetic testing is also done by hematologists for the same sake.