Thyroid Profile (T3, T4, TSH) at Shaukat Khanum Lab

Thyroid-stimulating hormone (TSH) is the first-line blood test when you have weight change, palpitations, hair thinning, irregular periods, or a neck swelling. A high TSH usually means an underactive thyroid; a low TSH often points to overactivity. Many Pakistani endocrinologists add free T4 only when TSH is abnormal.

Fasting is not required for TSH. Biotin supplements above 5 mg daily can falsely affect some immunoassays—stop them for two days if your lab advises. Take levothyroxine after the blood draw on the day of testing unless your doctor gives different timing instructions.