Causes of low thyroxine t4

Thyroid hormone t4 low may be hypothyroidism, but also need to be combined with t3, tsh test results comprehensive judgment, t3, tsh values are normal, may be caused by other reasons t4 decreased, do not need to deal with. If accompanied by t3 low, tsh high, consider primary hypothyroidism; if t3 low, tsh low, may be central hypothyroidism.