Perianal pain after running may be related to muscle damage, thrombosed hemorrhoids, proctitis and other reasons. 1. Muscle damage: If the patient lacks exercise for a long time, it may lead to muscle tension or muscle damage in the lower body after running, which may involve the buttocks and perianal area, thus producing perianal pain and other conditions. 2. thrombosed external hemorrhoids: thrombosed external hemorrhoids is mainly due to perianal subcutaneous blood vessel rupture, blood seepage into the skin or stagnation in the blood vessels, mainly manifested as swelling around the anus, pain, etc., especially after running and other strenuous activities, the pain is more obvious. 3. Proctitis: proctitis is a kind of inflammatory disease on the surface of rectal mucosa, which is mainly manifested as anus falling sensation, anxiousness and heaviness, bloody stool, mucus stool and other symptoms, for the more serious inflammation of the patient, after strenuous activities may cause perianal pain symptoms. It is recommended that patients seek medical examination in a timely manner to clarify the cause of the targeted treatment, pay attention to the monitoring of the condition in life, if the pain can not be significantly relieved, it is also necessary to go to the hospital for further examination, to exclude herniated discs and other diseases caused by the pain.