I am just copy-pasting here pages 155/156 from my book “Sex Problems: Causes, Cure and Prevention”, published in 2007. RM 10/-. ISBN978-957-9988-11-6, 224 pages, WITHOUT ANY BIT OF EDITING. (This book is also available as an e-Book from Mobipocket.com): This part comes under Chapter- 9:
Q.7. Is masturbation dangerous?
Answer: As a boy grows up, the reproductive parts of his body start functioning somewhere near his 11th or 12th year1. A natural urge develops in him, and without any one telling him, he ‘discovers’ the hidden pleasure associated with masturbation. Even if he develops some amount of fear, he continues to practice what he has newly found. If for any reason, he refrains, then, the semen leaks out while he is asleep, and we call it nocturnal emission. Thus, this occurs as a natural phenomenon.
Sexual union with a female does not create any friction heat in the male, but masturbation does. As a result of masturbation, entire body of the male becomes acidified. Daily masturbation can make the body hyperacidosed. This state of body reaction can give sore throat, common cold, flu and back pain. This will occur frequently in men with a thin body frame, and occasionally in obese people. No other danger may result due to masturbation.
In fact, if a person cannot have regular sex relations with his wife, it would be better for him to masturbate about once a week or so, for that would keep his reproductive system in an active and viable state. Prolonged abstinence from sex may instil impotency in a male, while at the same time, even sperm production may get reduced or stopped totally.
Answer in brief: Masturbation is not dangerous. However, anything in excess can be dangerous.
1 Boys who become obese because of under-urination, and not because of over-eating alone, come to maturity much later than the boys who drink plenty of water and void almost all of it through about 8 – 10 urinations. The obese tend to start masturbating only in their 13 or 14 at longer intervals. Whereas, the thin boys appear to be starting this habit even in their 10 or 11th year. A year later, these thin ones do it almost once, or even twice daily.