Alcohol and erectile dysfunction are often related causally, though the effects of alcohol on erectile dysfunction vary in the long and short term. In the short term, drinking can cause a man to lose the ability to achieve or maintain an erection. Drinking in the long term, on the other hand, can cause impotence due to the negative physical effects on the body from alcohol consumption. For most people, alcohol in moderation does not cause erectile dysfunction, although preexisting erectile dysfunction can be made worse with alcohol. Determining the relationship between alcohol and erectile dysfunction often requires considering other features of the user's physical condition.

Many people who experience problems with sexual activity due to alcohol and erectile dysfunction are not alcoholics, but rather people who have drunk too much to perform sexually. Alcohol can suppress the nervous system, making the body's physical response to sensations in normally sensitive areas less intense. As such, even if a man can achieve an erection under the influence of alcohol, it is not always possible to ejaculate.

For most men, alcohol and erectile dysfunction are related only through this numbing effect. Some people, though, find that after heavy drinking the dysfunction persists into the next day. This may be caused by alcohol's blood-thinning effects, making it difficult to maintain a solid erection.

When alcohol is consumed in moderation, it can sometimes help overcome erectile dysfunction that is caused by anxiety. Being controlled by inhibitions can fully prevent an erection, no matter how much a man wants to achieve one. Alcohol and erectile dysfunction do occasionally have a positive relationship, but it is not a good idea to build up the experience of sex in a way that will train the body not to become aroused without alcohol. Moreover, this positive relationship is dependent on drinking a reasonable amount, which may be difficult to maintain over a long night.

The long-term effects of heavy drinking or severe alcoholism are usually dire and negative. While a few drinks will not cause these negative effects, any person who consumes large quantities of alcohol on a regular basis is at risk of developing liver problems and experiencing generally impaired bodily function. There is no telling precisely which problems will cause the body to lose its ability to achieve an erection, but a person who is in poor health will certainly experience decreased sexual health as well. This kind of erectile dysfunction is often permanent, making it one of the most debilitating connections between alcohol and erectile dysfunction.