No it is NOT unhealthy to masturbate. Masturbation is a way that people express and explore their sexual feelings. It is when you touch or stroke your genitals to become aroused. People may touch their clitoris, their penis, their testes (balls) or around the genitals. 

Different people find different things erotic. Exploring your own body through masturbation can be a good way to find out about your sexual feelings and your body.

Masturbation is not bad for you. It's your choice whether you do it or not.