Generally speaking, no.
There are some men who become addicted to it, and others who try unsafe ways to achieve orgasm (such as using the suction from a vaccum cleaner) so in these minority of cases it can be.
Chat with our AI personalities
No. It will not cause excessive hair, blindness, hell, or anything else. It is natural and normal. Most people do it. It doesn't make sense that it would be harmful, because the act of sex in itself is not, and masturbation is just mimicking it. The only way masturbation could be a problem is if it interferes with everyday life.
Masturbation is useful because it gives you pleasure. But if you do it to much you might become sore.