My friend has been really tired recently and I told her it could be low thyroid. So she took my advice and asked the doctor for a thyroid test and has just got the results. Free T4 12.8 (12-22) and TSH 4.3 (0.3-4.2). I said it wasn't normal and that I would ask the wonderful members on healthunlocked for your opinions. She is 44 and in good health generally just very tired.