The redness and pain of the foreskin may be due to excessive sexual intercourse, trauma, and glans phimosis. 1. Excessive sexual intercourse: frequent sexual intercourse or excessive masturbation will cause excessive friction on the penile area, which will cause redness and pain of the foreskin. 2. Trauma: If the penis area suffers a violent impact, it will also cause local redness and pain. 3. circumcision: circumcision is the head of the glans has infection, trauma or irritation caused by inflammation, the more common is infection, most of the combination of circumcision, due to the long foreskin can not be thoroughly cleaned, bacterial growth of local inflammation, there will be skin and mucosal edema, erythema, vesiculation and ulceration, etc., there will be pain, irritation and itching sensation. The redness and pain of the foreskin may have other causes, the patient needs to consult a doctor in time for examination and treatment. Normally it is recommended to have regular sex and pay attention to personal hygiene.