It’s unlikely that the issue you are describing is due to masturbation; as a matter of fact, it may not be an issue at all. Variation in coloration along the shaft is not uncommon, and it can come and go for simple reasons (e.g., the manner in which blood is flowing and the hardness of the penis at the time, how much pressure has been exerted on the area recently, heat and sweat, etc.) One thing which might be beneficial is to use a good penis vitamin cream (health professionals recommend Man1 Man Oil). Ideally one with a range of vitamins, such as A, B5, C and E, can help to ensure good penile health.
Hello,
Masturbation is a harmless condition and most men and women masturbate. It is a way of relieving excess stress and anxiety towards sex.It has no permanent effect on the size of the penis and the scrotum nor does it affect the physical characteristics unless you have harmed it in any way. Our genitals and groins are hyperpigmented compared to other parts of body. A clinical examination may be necessary for exact diagnosis and treatment. If the problem is severe it is best to contact a doctor. Keep me posted.
Best luck and regards !