The smaller and smaller opening of the foreskin may be caused by trauma, circumcision, phimosis and other reasons. 1. Trauma: If a man’s penile foreskin is traumatized and hematoma occurs, it may cause adhesion problems, resulting in the foreskin not being able to be turned up and the foreskin opening becoming smaller and smaller. 2. Hyperextension of the foreskin: If the male foreskin lacks stretching power and the opening of the foreskin is narrowed, the problem of hyperextension of the foreskin may occur, and hyperextension of the foreskin leads to the phenomenon that the opening of the foreskin is getting smaller and smaller. 3. Circumcision: In daily life, men do not pay attention to the hygiene of the private parts, bacterial infection leads to circumcision, inflammation stimulates the penile foreskin adhesion, thus appearing in the circumcision opening is getting smaller and smaller. Patients with smaller and smaller circumcision should go to a regular hospital in time to clarify the cause of the disease, and take targeted treatment measures under the guidance of a professional doctor.