I have a doctor’s appointment coming up during the nine days. Can I remove facial and body hairs in preparation for the appointment during the Three Weeks?
If there is a medical need that requires you to remove facial hair, it is permitted. If there is no medical need, however, it is not perimitted to do so.
It is permitted to remove body hair (in the Three Weeks and the year round) if required for medical reasons.
Sources: If there is a medical need it is permitted to cut hair or shave, and this is certainly no worse than shorteninng a moustach that gets in the way of eating (Shulchan Aruch 551:13), or washing for medical purposes (which is permitted even on Tisha Be’Av itself, 554:15). If possible, it is better to shave before Rosh Chodesh Av, or at the very least before the commencement of the week of Tisha Be’Av.