The hair cycle normally consists of growing, resting and falling hairs and there is a delicate balance between these stages of hair cycle. Normally hair should re-grow but if it is not happening, you should consider seeing a dermatologist. Further information is in the following weblink https://www.aad.org/public/diseases/hair-and-scalp-problems/hair-loss A t3 alone do not convey the message, so meet a doctor and get further evaluation, You can understand it better as you are in medical profession.