Under normal circumstances, it usually takes only about 3 hours from the time the blood is drawn for thyroid function testing to the result, but the number of patients in the hospital is often high and the blood is usually drawn in the morning and the result is issued in the afternoon. Some patients who visit the hospital in the afternoon have their blood drawn in the afternoon and the report is often issued on the second day. Some hospitals have limited conditions and need to send specimens for thyroid function tests to other hospitals, in which case the test report can take 1-3 working days to be returned. Thyroid function is a routine test to diagnose whether a patient has a disease of the thyroid gland, and the test can diagnose whether a patient is suffering from hyperthyroidism or hypothyroidism. For this test, you should take rest and avoid straining. You should also avoid taking drugs that affect thyroid function, such as amiodarone, hormones, phenytoin sodium, etc.