ED or male impotence is when a man can’t get an erection that stays hard enough for sex. Most men will encounter the problem at least once in their lives, and it's understood to affect around half of all men aged between 40 and 70 to some extent. It can sometimes just happen sporadically, and resolve itself. But at other times it can persist and become a problem for couples when they want to have sex.
There are lots of reasons why it can happen. Physical causes can often be behind ED. Any medical condition that interferes with circulation, such as high cholesterol or diabetes, or with the transmission of nerve signals from the brain, can prevent a man from getting an erection. Lifestyle factors like smoking, drinking too much alcohol, being overweight or using recreational drugs can trigger ED too.
Emotions and psychology can also play a part. For example, men who are having sex with a new partner for the first time can sometimes feel eager to impress and put pressure on themselves to perform well. Stress is sometimes a factor as well, and this isn’t always necessarily related to sex.