Some men may have all the risk factors, obesity, high blood pressure, atherosclerosis, poor diet, smoke like a chimney and drink like a fish...and still not seem to have any problems in the bedroom.

They thicken and become less elastic. For most men however, the why is pretty evident. It would be comforting to say some version of it's a mystery, and be done with it.

They don't understand, at least not yet, why they are troubled. There's a big difference between why you have ED and what causes ED. It can cause arteriosclerosis, or hardening/furring of the arteries. Lifestyle factors, diet, exercise, weight, smoking, alcohol, are right at the top of the list of what can get you into trouble. But it would also be really annoying. Others seem to be in great health, exercise, pay attention to their diet and still have trouble. Yet, for some men, it is a mystery. Not just the arteries in your head, heart or legs but in your penis as well.

The very place you want them to be flexible and elastic.