Prostate hyperplasia. Coloured light micrograph of a section through a prostate gland with benign prostatic hyperplasia (BPH). BPH consists of excessive proliferation (growth and division) of cells in the prostate, causing it to become enlarged. This is a common condition in men aged 50 plus and is harmless if the nodules remain small. If the prostate continues to enlarge, it can put pressure on the urethra (the tube through which urine exits the bladder) and block it. Symptoms include frequent urination, increased urinary tract infections, and urinary retention. Treatment is with medication (alpha blockers). In severe cases, surgery to remove the affected area of the prostate may also be needed.