Masturbation does not cause a short penis, even if it is prolonged. Penis development is mainly determined by genetic factors and the endocrine function of the testes. Masturbation will not change the innate genes. The secretion of androgens by the testes can promote the development of the penis, androgens are mainly secreted by the testicular interstitial cells. Masturbation will not cause the function of testicular interstitial cells to change, so long-term masturbation will not affect its normal hormone secretion function. Masturbation is one of the ways to supplement sexuality and sexual needs, which is usually a normal physiological need. When it can not be satisfied by normal ways, usually take the above ways to satisfy sexual desire, which is an important supplemental way of sexual life. Generally speaking, there is no excessive masturbation, which has almost no effect on the human body. If you do not pay attention to hygiene, it is easy to cause inflammation of the genitourinary system, and even psychological dependence. So the normal number of masturbation is not too much damage to the human body, so it is recommended to masturbate appropriately and pay attention to hygiene.