Indeed, only people have hemorrhoids. This is because of the fact that among the creatures of nature, only man is an upright walking advanced vertebrate, while all others are reptiles. A very important point of difference between an upright human and a reptile is that the distribution of blood vessels in the anus and the tension in the anus are different in the two. Although people and animals at birth, the blood vessels and muscles in the anal area are similar, but with the continuous growth, activity increased, upright people in addition to the same as reptiles in the defecation is exertion, there is a reptile does not exist on the earth to the vertical gravitational force on the anal blood vessels, coupled with the people in the labor of fatigue, disease and diet of many factors, so that the human anal area of the venous blood vessels of the The resistance to reflux increases, over time occurred muscle tension relaxation, decreased vascular elasticity, venous mass accumulation, so hemorrhoids occur. Therefore, it can be said that hemorrhoids or a human “patent” it.