Q: I am 24 years old and just starting to thin. I was told by another doctor that it was too early to have a hair transplant, but the hair on the back and sides of my scalp seems really thick. Shouldn’t I have a hair transplant now, just in case I am not a candidate in the future? — A.S., Cherry Hill, NJ

A: The most important criteria in determining who will be a candidate for a hair transplant is the presence of sufficient permanent donor hair. When hair loss is early, it is often hard for the doctor to determine this, since early on the donor area can appear very stable. It is not until the front and/or top of the scalp has significant thinning that the donor area may also show thinning. Therefore, it is only at this time that the stability of the donor area can adequately be assessed.