Hemorrhoids (commonly known as hemorrhoids) is a common disease located in the anus, which can occur at any age, but with the increase of age, the incidence rate gradually increases. Etiology There are two main theories about the etiology of hemorrhoids. The first is varicose vein theory, which holds that hemorrhoid is a venous mass formed by blood stasis, expansion and flexion of venous plexus under submucosa of lower rectum and skin of anal canal. At present, however, the widely accepted theory is Thomson's theory of anal pad moving down, which holds that hemorrhoids are the normal anatomical structure of anal canal, that is, vascular pad, which is an annular spongy tissue belt with toothed lines above 1.5cm. Only when the anal pad tissue is abnormal and complicated with symptoms, it is called hemorrhoids and needs treatment. The purpose of treatment is to relieve symptoms, not to eliminate hemorrhoids. There are many inducing factors of hemorrhoids, among which constipation, long-term drinking, eating a lot of irritating food and sedentary are the main inducing factors. Classification Hemorrhoids are divided into internal hemorrhoids, external hemorrhoids and mixed hemorrhoids according to different parts. There is a jagged visible line at the junction of anal canal skin and rectal mucosa, which is called anal canal dentate line. Above the dentate line is internal hemorrhoid, and the supporting structure of anal pad, venous plexus and arteriovenous anastomosis branch is diseased or displaced, covering the rectal mucosa. Due to the contraction of the internal sphincter, the anal pad is divided into three parts: the left side, the right front side and the right rear side with a Y-shaped groove, so internal hemorrhoids are common in the left side, the right front side and the right rear side. Below the dentate line are external hemorrhoids covering anal mucosa, which can be divided into connective tissue external hemorrhoids, varicose external hemorrhoids and thrombotic external hemorrhoids; Mixed hemorrhoids with internal hemorrhoids and external hemorrhoids are the fusion of internal hemorrhoids and corresponding external hemorrhoids through venous plexus, that is, the anastomosis of upper and lower venous plexus. When the mixed hemorrhoid emerges from the anus and is plum blossom-shaped, it is called circular hemorrhoid. If incarcerated by sphincter, incarcerated hemorrhoids will be formed. The clinical manifestation is 1. The main manifestation is bloody stool, which can be painless, intermittent, bloody after defecation, dripping blood during defecation or blood on toilet paper, and aggravated after constipation, drinking or eating irritating food. 2. Simple internal hemorrhoids have no pain, only the feeling of swelling, which can bleed and develop into prolapse. Pain only occurs when thrombosis, incarceration and infection occur. 3. Internal hemorrhoids are divided into 4 degrees. (1) Bleeding during first-class defecation can stop automatically after defecation, and hemorrhoids do not leave the anus; ② There are often bloody stools in degree Ⅱ; The anus comes out during defecation and automatically returns after defecation; (3) Hand-assisted reflux after third degree hemorrhoid prolapse; Ⅳ degree hemorrhoids are outside the anus for a long time and cannot regenerate; Among them, internal hemorrhoids with degree ⅱ or above often form mixed hemorrhoids, which are characterized by the coexistence of internal hemorrhoids and external hemorrhoids, and may cause pain, discomfort and itching, among which itching is often caused by viscous secretions flowing out when hemorrhoids prolapse. Most of the last three degrees are mixed hemorrhoids. 4. External hemorrhoids usually have no special symptoms, and there may be swelling and pain when thrombosis and inflammation occur.