Generally it depends upon the diagnosis. Mostly patients suffering from baldness that cannot be cured with medicines undergo this procedure. Before going for this procedure patient has to disclose any other disease or medications that he/she is using.
One must have good number of hair follicles. Specific pattern of hair loss, emotional distress, thin and receding hair line and hair density also determine the probability of this procedure. Age also plays important factor but not in all the cases. There are certain diseases like alopecia areata in which individuals own immunity system damages the hair follicles and in such a condition this treatment has no more significance.