Erection
ED is not uncommon. For example, about 10% of all men in the United Kingdom will have ED happening to them regularly at some time in their lives. It can be due to both physiological and psychological reasons. Physiological reasons are those dealing with how the body works. Psychological reasons are those involving human behaviour and how people think. It is normal for male teenagers and men to have an erection several times per night when sleeping. If this does not happen, the person may have a bad medical (physiological) problem and should ask a doctor. If the man does have erections while sleeping, but can't get an erection to have sex, the man could have a mental health problem.