London: Half of the British men develop impotence at some point, with alcohol largely to be blamed.
The delicate nature of the subject means that many suffer in silence, with crashing self-esteem and relationships.
Boots, a chemist chain, surveyed 4,500 men. It found that 19 percent have struggled to make love when sober, while a further 31 percent have suffered problems after a boozy night out.
Some 68 percent of those polled also owned up to having experienced premature ejaculation at some point in their lives, reports the Daily Mail.
Two-thirds of married men said they would refuse to discuss the issue with their doctor and one in eight was so embarrassed that he would not talk about it with anyone.
Colm O`Mahony, consultant physician in sexual health at Chester Hospital, said: "Although extremely widespread, the taboo nature of these problems means that most sufferers do not seek help.
"Stigma, shame, concern for their partner`s reaction, and sometimes denial, all play a part. Many endure in silence, believing that the problem is transient, and that no help is available.
"It can be crushing. Guys get worn down and when you fix them, the change in their demeanour is dramatic.
Sexual problems are most common among older men, with causes including obesity, smoking, alcohol, stress, medication and hardening of the arteries.
Although Viagra is the best-known treatment, other drugs are also available. Premature ejaculation, which can also be exacerbated by stress, tends to hit younger men and is usually treatable by changes in sexual technique.