Urethritis is inflammation of the urethra, which is the tube that carries urine from the bladder. It is usually caused by a viral or bacterial infection entering the urethra. Common symptoms include pain or burning during urination, urges to urinate frequently, and discharge or blood in the urine. Risk factors include multiple sexual partners and unprotected sex. Diagnosis involves examination and urine testing, and treatment consists of antibiotics or antiviral medication.