Urethritis is inflammation of the urethra (the tube running from the bladder to the tip of the penis). Urethritis is normally caused by an STI but if the cause is unknown, it's called non-specific urethritis (NSU). NSU can make your penis sore. Symptoms of NSU include: a white or cloudy discharge from the tip of your penis a burning or painful sensation when you urinate the tip of your penis may feel irritated and sore a frequent need to urinate ::: body-ad-mobile zones:: 232632,232515,227375,232642 types:: 5 disclaimer:: ADVERTISEMENT typeFilter:: display adCount:: 1 :::