A dozen years ago I had a bout of hyperthyroidism - Graves Disease - that nearly resulted in a thyroid storm after hip surgery. A sharp hospitalist caught it right away & I was treated with methimazole. The endocrinologist monitored to see if would resolve itself, because we knew the cause & it had been alleviated.
After 18 months, we were ready to resort to thyroid irradiation when I began to get normal readings. Stopped the methimazole & the readings stayed normal - I am still monitored annually by my primary and my ophthalmologist and every 3 years by endocrinologist. Unfortunately, the tremor and heat intolerance/extreme sweating have decided to be my lifelong companions.