Hidden pain in the head of the penis when urinating may be caused by circumcision, prostatitis, urethritis, urethral stones and other causes. 1. Circumcision: Due to phimosis or phimosis, the sebaceous glands secreted or the residual foreskin scale may cause infection and inflammatory reaction. When the patient urinates, the head of the penis will be stimulated and cause pain. 2. Prostatitis: Prostatitis may occur due to prolonged lower urinary tract infections, fatigue, frequent sex, etc., and the urethra may be stimulated, so the penis head may also be painful when urinating. 3. Urethritis: Due to the retrograde infection of pathogenic bacteria into the urethra, causing the occurrence of urethritis, there may be the symptom of hidden pain in the head of the penis when urinating. 4. Urethral calculi: Due to the presence of stones in the urethra, stimulation of the mucous membrane of the urethra may cause congestion and edema, which will radiate to the head of the penis when urinating, thus causing pain. The pain in the head of the penis when urinating may also be caused by other reasons, it is recommended that the patient go to the hospital in a timely manner, to clarify the cause of the disease and then actively treat it, so as not to delay the condition.