Erectile dysfunction (ED) is the inability to get or maintain an erection during sexual activity. It affects men in their late teens and early twenties. ED can be caused by stress, anxiety, depression, lack of exercise, smoking, certain medications and alcohol abuse. There are many treatment options available, but not all treatments are effective. more information on ED treatment, including a discussion of common treatments such as prescription medications, herbal remedies, vitamins and homeopathic remedies, as well as alternative methods of treatment.