The Clinical Relevance of Platelet Function Tests

S ummary . The increasingly used tests of platelet function have been briefly reviewed and an attempt has been made to correlate the result of these tests with their clinical significance. It may be said that the platelet count and bleeding time are still the most important information for the clinician. It has seldom been shown that isolated abnormalities of morphology, adhesion, aggregation or platelet factor 3 release have any clinical relevance unless accompanied by a prolongation of the bleeding time. A long bleeding time in an otherwise healthy patient is most frequently due to aspirin ingestion.