Fasting is not usually required for a 7-phase thyroid test. However, it is necessary to avoid excessive eating, especially avoid eating a lot of sugary and greasy food. The 7-item thyroid function test includes TSH, total T3, free T3, total T4, free T4, TPOAb, TGAb, and the test items may vary from hospital to hospital. It is mainly used to check thyroid function and determine the presence of hypothyroidism, hyperthyroidism, thyroid autoimmune disease and other conditions. Normal diet has no effect on the thyroid function measurement, so fasting is not required on the day of blood sampling. However, you should avoid eating too much, especially not after eating a lot of sugary or greasy food. You should have a regular routine before the blood test and should not be over-stressed. People who need to undergo the 7-phase thyroid function test should actively cooperate with the healthcare personnel, and are advised to go to the hospital if there is any abnormality in the thyroid function.