ED can be caused by a handful of things, but one thing’s for sure: You need a healthy supply of the neurotransmitter nitric oxide (NO) to get and maintain an erection. NO is produced in nerve tissue and helps jolt your Johnson by relaxing the smooth muscle so blood can fill the penis. After the initial release of NO, your body releases a cascade of chemicals—including more of the neurotransmitter—to help keep you hard and happy, according to a study in the Proceedings of the National Academy of Sciences.
Erectile dysfunction (ED) is commonly called impotence. It’s a condition in which a man can’t achieve or maintain an erection during sexual performance. Symptoms may also include reduced sexual desire or libido. Your doctor is likely to diagnose you with ED if the condition lasts for more than a few weeks or months. ED affects as many as 30 million men in the United States.