Causes

Scar tissue, which can narrow the urethra, can be due to:

• A medical procedure that involves inserting an instrument, such as an endoscope, into the urethra
• Intermittent or long-term use of a tube inserted through the urethra to drain the bladder (catheter)
• Trauma or injury to the urethra or pelvis
• An enlarged prostate or previous surgery to remove or reduce an enlarged prostate gland
• Cancer of the urethra or prostate
• Sexually transmitted infections
• Radiation therapy

Urethral stricture is much more common in males than in females. Often the cause is unknown.