Hemorrhoids occur due to the special anatomical location of the anus. First, because the anus is located in the end of the digestive tract, the upper rectal venous plexus has no venous valve, standing position is easy to cause blood reflux obstruction; Second, when the intra-abdominal pressure increases, such as constipation, long-term diarrhea, pregnancy, pelvic mass, can make venous reflux obstruction, so that the venous plexus enlargement of the varicose; Third, the body is weak and emaciated, tissue laxity, the veins are easy to dilate or systemic diseases such as liver cirrhosis, portal hypertension so that the blood reflux obstruction; In addition. In addition, local inflammation and spicy stimulation, drinking alcohol, smoking, etc. can make the rectal mucosa congested and hemorrhoids occur.