Not a true disease, Webster, but a psychological disease. Much in the same way that homosexuality is a pyschological disease, that is, it was a psychological disease because of religious and cultural pre-dispositions. As if women don't have the right to screw whatever they want to screw. Co-incidentally, one of the most famous prescriptions for nymphomania and Female Anxiety was the vibrator, first used to treat these 'diseases' in the 1890s.

Is nymphomania dangerous? Perhaps, through the possible spread of Sexually Transmitted Diseases. However, this poses no more risk than any other excess. It is nobody's business other than your own and the people you choose to share that observation with if you are a nymphomaniac. Although, this is not to say one should be allowed to hold a disregard for human life should someone be knowingly transmitting sexual diseases.