Adam:
Nope. Masturbation has had a bad rep ever since the Biblical story of Onan. (Mel Brooks has observed, "He was supposed to be fruitful and multiply, but he was fruitless, and subtracted.") But masturbation doesn't cause hair on the palms, weakening of the body's
vitalVital-d humors, or any other disease (other than perhaps some mild redness from friction, which readily goes away.)
Good night.
Dr. Rockoff