Hemorrhoids are medically known as hemorrhoids. There are two theories of the etiology of hemorrhoids: the varicose vein theory and the inferior displacement of the anal cushion theory. The varicose vein theory considers hemorrhoids to be a bulging venous mass formed by tortuous, dilated veins in the lower rectum or terminal anal canal. In contrast, recent medical research is based on the anal cushion theory, which states that hemorrhoids are pathological hypertrophy of the normal anal cushion in the upper part of the anal canal. The anal cushion includes the rectal mucosa and submucosal vessels, the anal canal skin and subcutaneous vessels, and fibrous connective tissue. The anal cushion is a normal tissue of the body and is only considered a pathological condition when it becomes overgrown and symptomatic, which is known as “hemorrhoids”. Clinically, there are 3 types of hemorrhoids depending on where they occur: internal hemorrhoids, which occur above the dentate line; external hemorrhoids, which occur below the dentate line; and mixed hemorrhoids, which occur both above and below the dentate line and are connected together. Internal hemorrhoids can be divided into three stages according to the degree of severity: Stage 1: Small nucleus, blood during defecation, blood on the hand paper after defecation, dripping or shooting blood, no pain, no swelling out of the anus. Physical examination reveals granular protrusion of the hemorrhoidal mucosa, soft and bright red in color. Stage II: The nucleus of hemorrhoid is enlarged, the mass prolapses outside the anus during defecation, and can be retracted by itself after defecation, which can be accompanied by fresh blood, anal swelling, extra-anal dampness, pain and itching, and the anal opening cannot be wiped clean after defecation. The physical examination shows that the mucous membrane is thickened, such as moldy thorns, red, sometimes dark red. Stage 3: It is the late stage of internal hemorrhoid, the nucleus of hemorrhoid is larger, the nucleus of hemorrhoid can be prolapsed outside the anus after defecation, even when coughing, exerting, walking and working, and it must be sent back to the anus by hand, or it can be returned to the anus after resting. Physical examination shows roughness and partial fibrosis on the surface of the hemorrhoid, and there may be arterial pulsation in the parent hemorrhoid area. (1) Vascular swelling type The mucous membrane on the surface of internal hemorrhoids is rough and soft, dark red or vermilion in color, and bleeds easily when touched, and bleeding is the main symptom of this type. This type has bleeding as the main symptom. First-stage internal hemorrhoids are common, but third-stage hemorrhoids do not have this symptom. (2) Phleboma type The surface of internal hemorrhoid is hard, with luster, dark red or greenish purple, and there are varicose hemorrhoidal veins and hyperplastic connective tissue inside the hemorrhoid. This type of internal hemorrhoid is not easy to bleed, and there are more internal hemorrhoids in the second and third stages. (3) Fibrosis type The surface of internal hemorrhoids is hard and elastic, and the surface of the hemorrhoid body is slightly proliferated with white fibrous tissue, which can easily come out and not bleed easily. The third stage internal hemorrhoids are the most common, while the first stage does not have this symptom. External hemorrhoids are mainly raised swellings on the anal side and can be divided into the following types: (1) Thrombosed external hemorrhoids Sudden appearance of painful lumps at the site of existing varicose veins in the anal canal. The local examination reveals a bulging swelling next to the anus, and a hard nodule can be palpated under the skin. This is mainly due to the rupture of blood vessels after excessive activity or constipation, which causes blood to seep into the subcutaneous area and form a thrombus. (2) Inflammatory external hemorrhoids Swelling and pain at the anal verge. Local examination reveals a swollen mass next to the anus, with obvious congestion and edema and tenderness. It is mainly formed by edema after chronic inflammatory stimulation due to skin injury or inflammatory attack at the anal verge. (3) Varicose external hemorrhoids Single or multiple raised lumps at the anal verge, which prolapse during stool and can be retracted by themselves or by hand after stool, sometimes accompanied by post-poo swelling and pain. (4) Connective tissue external hemorrhoids The masses that protrude outside the anus, shaped like flab, are proliferating mechanized skin flaps caused by the skin folds at the anal verge, and are usually painless. If the acute attack can be transformed into inflammatory external hemorrhoids, accompanied by pain, foreign body sensation at the anus, often accompanied by itching at the anal opening due to unclean wipe after defecation. Mixed hemorrhoids can be divided into the following four types according to their number: (1) Simple mixed hemorrhoids (2) Multiple mixed hemorrhoids (3) Circumferential mixed hemorrhoids (4) Complex mixed hemorrhoids