What tests are used to find low platelet count?

The tests used to find low platelet count include physical examination, blood tests and ultrasound, states Healthline. Other tests for low platelet count are bone marrow aspiration and biopsy.

A physical examination involves checking the patient's body for excessive bruising or petechiae, explains Healthline. A doctor also checks for an enlarged spleen, which can cause a low platelet count, by feeling the patient's abdomen. In addition, the doctor may review a patient's family history for bleeding disorders to determine if the bleeding is hereditary.

Doctors perform a complete blood count test, which helps determine the quantity of blood cells in the body, claims Healthline. Blood tests also involve testing for platelet antibodies to determine if a low platelet count is medication induced as a result of taking certain medications such as quinine. These antibodies destroy blood platelets.

Blood-clotting tests, which include partial thromboplastin time and prothrombin time, are other methods that a doctor uses to find low platelet count, notes Healthline. These tests involve adding certain chemicals to a blood sample to establish the length of time blood takes to clot.

Ultrasound involves the use of sound waves to produce a picture of the spleen, according to Healthline. The picture helps the doctor determine if the spleen is enlarged or not.