For a non medico, I would say Prostate is an organ which is present below urine bladder. It usually becomes swollen in old men and causes urine obstruction as the grade increases. For this patient grade is 3. He has to visit urologist for further treatment. After complete tests, a surgery to peel the swollen Prostate may be needed to make the urine floe freely. Till surgery if urine cannot be passed, then a catheter/tube may be kept for free urine flow.