Smoking can have a huge impact on a man’s erections. In fact, in 2014 the acting U.S. Surgeon General added erectile dysfunction (ED) to the list of conditions that can be caused by smoking.

Research has shown that men who smoke are at higher risk for ED. Often, erection problems are worse for men who smoke heavily and those who have smoked for a long time. Secondhand smoke may also interfere with erections.

To get a firm erection, a man needs to have sufficient blood flow to his penis. This is what keeps the erection firm enough for sexual activity.

Chemicals from smoking can interfere with this blood flow. Smoking can damage the lining of blood vessels or lead to atherosclerosis (hardening of the arteries). It can also affect the smooth muscle tissue that needs to relax to allow blood to flow in.

When any of these scenarios occur, less blood can reach the penis. Men may become unable to have erections. Of if they can, the erections are weak.

Smoking can also decrease amounts of nitric oxide, a compound that plays an important role in erections.

ED often gets better when men quit smoking. Still, men who are having trouble getting and keeping a firm erection are encouraged to see their doctor. Many factors, not just smoking, can contribute to ED. Health conditions like diabetes or heart disease can be involved, too. If that’s the case, it’s important for those conditions to be treated. Doing so is not only good for overall health, but it could improve erections.

In the meantime, quitting smoking is always a good idea – the sooner the better. A doctor can suggest methods for quitting or make a referral to a smoking cessation program.