Generally, a fasting blood draw is not required for thyroid function tests. However, if patients want to test their blood sugar and liver function at the same time, they need to draw blood on an empty stomach. Common thyroid function tests include TSH, total T3, free T3, total T4, free T4, TPOAb, TGAb, etc. A fasting blood draw is generally not required for simple thyroid function tests. However, it is necessary to avoid excessive eating, especially after eating a lot of sugary food. Blood should be drawn in a quiet state, avoiding strenuous exercise and emotional stress. If you want to have your blood drawn to check your blood sugar and liver function at the same time as your thyroid function, you will need to have your blood drawn on an empty stomach. Please consult your doctor for specific precautions for blood tests for thyroid function.