Subclinical hypothyroidism. To treat or not to treat

The term subclinical hypothyroidism has been used to describe the syndrome of high serum levels of thyroid-stimulating hormone associated with normal levels of thyroid hormone. Diagnosis requires a sensitive method of measuring TSH. Because the syndrome does not invariably lead to overt hypothyroidism, it would not be appropriate to institute lifelong levothyroxine therapy in every case. Cases that do not qualify for immediate therapy need close follow up.