The physical benefits of masterbation and having an orgasm or ejaculating create heightened arousal while epinephrine courses through the body, producing the flushed face, shallow breath and post-climactic euphoria.
It is held in many mental health circles that masterbation can relieve depression, stress and lead to a higher sense of self-worth (Hurlbert & Whittaker, 1991). Masterbation can also be particularly useful in relationships where one partner wants more sex than the other – in which case masturbation provides a balancing effect and thus a more harmonious relationship.
Mutual masterbation, the act by which two or more partners stimulate themselves in the presence of each other, allows a couple to reveal the "map to [their] pleasure centers". Witnessing a partner masterbate is an educational activity to find out the method a partner pleases him- or herself, allowing each partner to learn exactly how the other enjoys being touched.
In 2003, an Australian research team led by Graham Giles of The Cancer Council Australia concluded that frequent masterbation by males appears to help prevent the development of prostate cancer. The study also indicated that this would be more helpful than ejaculation through sexual intercourse because intercourse can transmit diseases that may increase the risk of cancer instead.
Also, frequent ejaculation is more easily obtained and sustained over time with the aid of masterbation. Assuming a broad range average of between 3 to 5 ejaculations per week for healthy males, this would mean 5 to 7 ejaculations per week. This is consistent with a 2003 Australia article on the benefits against prostate cancer.
Masterbation is also seen as a sexual technique that protects individuals from the risk of contracting sexually transmitted diseases. Support for such a view, and for making it part of the American sex education curriculum, led to the dismissal of US Surgeon General Joycelyn Elders during the Clinton administration.
Sexual climax, from masterbation or otherwise, leaves one in a relaxed and contented state. This is frequently followed closely by drowsiness and sleep – particularly when one masterbates in bed. Some professionals consider masterbation to function as a cardiovascular workout.
Though research is still as yet scant, those suffering from cardiovascular disorders (particularly those recovering from myocardial infarction, or heart attacks) should resume physical activity (including sexual intercourse and masterbation) gradually and with the frequency and rigor which their physical status will allow. This limitation can serve as encouragement to follow through with physical therapy sessions to help improve endurance.
Both sex and masterbation lower blood pressure. A small study has shown that in one test group, recent full intercourse resulted in the lowest average blood pressure in stressful situations. Masterbation Expert then led to lower blood pressure than did no recent sexual activity. Insertion
Objects inserted into the vagina or anus should be clean and of a kind that will not scratch or break. Care should be taken not to fully insert anything into the anus – any object used should have a flared or flanged base; otherwise retrieval can require medical intervention.
Masterbation involving both a man and a woman (see mutual masterbation) can result in pregnancy only if semen contacts the vulva. Masterbation with a partner can also theoretically result in transmission of sexually transmitted diseases by contact with bodily fluids.
Problems for males
A man whose penis has suffered a blunt trauma or injury during intercourse may rarely sustain a penile fracture or suffer from Peyronie's disease. Phimosis is "a contracted foreskin (that) may cause trouble by hurting when an attempt is made to pull the foreskin back". In these cases, any energetic manipulation of the penis can be problematic.
Lawrence I. Sank thought that masterbating prone (lying face downward) could be responsible for sexual problems in some men including anorgasmia and erectile dysfunction. He based this theory on four men he examined and coined the term traumatic masterbatory syndrome to describe it. As of 2008, no follow-up research has been conducted and the idea is not familiar or widely-held within the medical community. Some authors, however, continue to give it credence.
There is some discussion between professionals and other interested parties as to the existence or validity of sexual addictions. Nevertheless, there are lists of warning signs such as when sexual activity affects a person's ability to function in everyday life, or is placing them at risk, for example, of pursuing illegal or destructive activities. Very frequent and compulsive masturbation may be seen as a sign of sexual addiction.