One of the most underestimated causes of impotence, also known as erectile dysfunction, is actually cigarette smoking. We know that cigarette smoking contributes to atherosclerosis (the build-up of plaque) that hardens arteries. Nitric oxide production is important in maintaining healthy blood vessels. It signals the inside of the blood vessels to increase blood flow to organs to keep the blood vessels plaque-free. Smoking interferes with nitric oxide, causing the blood vessels to narrow, or constrict, decreasing blood flow to the penis (and other organs), and over time prevents the blood vessels in the penis from being able to engorge with blood to produce an erection. Obviously, the greater the length of time spent smoking, the greater the damage to the biological systems that cause impotence and the more difficult it is to treat it. Of course, smoking is a difficult habit to quit, but perhaps you should consider a smoking cessation program to benefit your sex life and general health. It is a good idea to consult a primary care doctor for more information or management of erectile dysfunction, should you suspect you are developing it.