Hemorrhoids are divided into three categories, internal hemorrhoids, external hemorrhoids as well as mixed hemorrhoids, the three types of hemorrhoids have different physiological sites and different organizational structures, the specific distribution location as well as structure as follows. 1. external hemorrhoids: external hemorrhoids are clearly differentiated from the other two types, external hemorrhoids are located entirely around the anus, occurring below the dentate line of the anal canal, is formed by the subcutaneous venous plexus pathologic dilatation, thrombosis, and connective tissue hyperplasia, the surface of the skin of the anal canal is covered by the skin, including: thrombosis hemorrhoids, inflammatory hemorrhoids, connective tissue hemorrhoids, varicose external hemorrhoids. 2. internal hemorrhoids: located above the dentate line of the rectal mucosa under the vascular plexus dilatation, the essence of the expansion of the venous blood vessels to form a mass-like material. 3. Mixed hemorrhoids: internal hemorrhoids and parts of external hemorrhoids fused with each other to form, mainly or varicose venous vascular plexus as well as connective tissue hyperplasia caused by each other. For different types of hemorrhoids, clinical manifestations are not the same, the patient needs to consult a doctor in time, a clear diagnosis, active treatment.