There are many factors to cause deficiency of perfect rigidity. Main five aspects are as followed:

Killer one: Mental pressure is too over. Affected by intensive and fast rhythm lifestyle of modern society, middle age male shoulder huge pressure of working, life and society.

Killer two: bad lifestyle. Long-smoking and drinking too much will cause difficulty of erection. Even if they can erect grudgingly, they would ejaculate too soon. The chance of erecting again will decline.

Killer three: inanition. Nutrition is very important for people's energy. Under-nutrition and over-nutrition would lead to men’s sterility

Killer four: diseases. Experts said that Body disease has direct relationships with decrease of sexual function. The reason for that is that body diseases like hypertension, hyperlipemia, diabetes and arteriosclerosis would cause enough blood incapableof flowing into penis.

Killer five: drugs. Study shows that if sufferers take hypotensor, antidepressant, hormone and anticarcinogen etc. that would cause ED.