Also, stress from outside of the relationship or problems due to past sexual experiences may lead to sexual problems. Simple lack of knowledge often is a problem, either in not understanding what is physically or psychologically normal or in being inexperienced with sexual matters. Impotence, although it can be caused by physical problems, is most commonly due to psychological causes. Often, the original episode of impotence results from stress, physical exhaustion, or having had too much alcohol to drink. This can then lead to anxiety that can interfere with subsequent sexual encounters, causing further failure, and so on, until failure becomes the general rule.
Premature ejaculation is a common problem.
This occurs when ejaculation occurs before or almost immediately after insertion of the penis into the vagina. Commonly, this occurs due to anxiety, inexperience, or extreme arousal. This can result in the man feeling that he has failed, and the woman feeling unsatisfied and frustrated. Vaginismus occurs when the woman's vaginal muscles go into spasm and prevent penetration by the man's penis. In contrast, frigidity occurs when the female has difficulty becoming aroused.