Platelet Function Tests

Platelets are vital for normal blood clotting. Produced in the bone marrow, they circulate in the blood until they are needed in a clot forming process. If there are not enough platelets, or if they are not working normally, a patient may be at an increased risk of excessive bleeding. The number of platelets can be easily determined with a platelet count, but the overall platelet function is more difficult to measure. Unfortunately, there is no one test that identifies all problems with platelet function.

Platelet function tests are used to screen at-risk pre-surgical patients to determine whether they are likely to bleed excessively during an invasive procedure. There is no good platelet function screening test to predict which patients are likely to bleed during surgery.


Normal values depend on many factors. Your lab will provide a range of normal values with your test results.

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.


Your caregiver will go over your test results with you and discuss the importance of this test. Reference values are dependent on many factors. Numeric test results have different meanings in different labs. Your lab report should include the specific reference range for your test.


It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.