Following a detailed discussion about the history of erectile dysfunction and its risk factors, your doctor will examine the testicles and penis to help determine the cause of erectile dysfunction. Your doctor will check reflexes and pulses in the area to see if problems with blood vessels or nerves are contributing to the erectile dysfunction. If necessary, your doctor will order tests to help diagnose erectile dysfunction.
ED usually has a multifactorial etiology. Organic, physiologic, endocrine, and psychogenic factors are involved in the ability to obtain and maintain erections. In general, ED is divided into 2 broad categories, organic and psychogenic. Although most ED was once attributed to psychological factors, pure psychogenic ED is in fact uncommon; however, many men with organic etiologies may also have an associated psychogenic component.
The history can be useful in distinguishing organic from psychogenic impotence (Table 187.1). The patient with organic impotence describes problems with erection that progress over months to years. At first, the patient will have partial erections or seemingly firm erections that become flaccid during intercourse. With time, total erectile failure ensues. Organic impotence is constant and nonselective, meaning it is not better or worse with any specific partner or any type of stimulation.
Sexual dysfunction is highly prevalent in men and women. In the MMAS, 52% of the respondents reported some degree of erectile difficulty. Complete ED, defined as (1) the total inability to obtain or maintain an erection during sexual stimulation and (2) the absence of nocturnal erections, occurred in 10% of the respondents. Mild and moderate ED occurred in 17% and 25% of responders, respectively. 
The rumors are true. Having too much to drink can interfere with a man’s ability to have an erection. According to Everyday Health, alcohol is a depressant. This means that, along with dampening your ability to think, speak, and move efficiently, it can also dampen mood, decrease sexual desire, and make it difficult for a man to achieve erection or reach an orgasm. This is because alcohol decreases blood flow to the penis. That not only may reduce a man’s ability to have an erection, but even if he is lucky enough to get it hard, alcohol can reduce the intensity of his orgasm.
Some may use alcohol as a way to get into the mood and overcome some of the nerves associated with having sex, but too much of a good thing can actually backfire. In fact, having a long history of alcohol abuse may lead to long-term erectile dysfunction. As many as 70 percent of men with chronic erectile dysfunction also have a history of alcohol abuse.
Having erection trouble from time to time isn't necessarily a cause for concern. If erectile dysfunction is an ongoing issue, however, it can cause stress, affect your self-confidence and contribute to relationship problems. Problems getting or keeping an erection can also be a sign of an underlying health condition that needs treatment and a risk factor for heart disease.