 [ Symptoms ] how is hypothyroidism diagnosed [ Disease ] if you have symptoms of hypothyroidism your doctor will order blood tests to check hormone levels these may include thyroid stimulating hormone tsh t4 thyroxine lower than normal t4 levels usually mean you have hypothyroidism however some people may have increased tsh levels while having normal t4 levels this is called subclinical mild hypothyroidism it is believed to be an early stage of hypothyroidism if your test results or physical exam of the thyroid are abnormal your doctor may order a thyroid ultrasound or thyroid scan to check for nodules or inflammation