The urethra is the muscular tube that runs from the bladder to the external urethral orifice where it carries urine from the bladder to be expelled into the environment. In men, the urethra traverses the prostate gland, passes along the penis to terminate at the glans penis (penis tip). With women, the urethra is much shorter, runs against the anterior vagina wall to terminate in the vestibule between the clitoris and vaginal orifice.
Along its course, the urethra can become narrowed either due to pathology within the urethra (intrinsic) or from surrounding structures that compress the urethra (extrinsic). The urethra varies in diameter and the point where the urethra narrows due to any swelling or scarring of the urethral wall is known as a stricture. Although a urethral stricture is more likely to occur in men due to the longer urethra, overall a urethral stricture is rare. Other problems may cause an obstruction within the urethra, like urinary stones, and cause similar symptoms to that of a stricture.
Signs and Symptoms of Urethral Narrowing
A narrowing of the urethra can be asymptomatic and remain silent throughout life. The most common symptoms of urethral strictures are :
- difficulty passing urine (voiding) – hesitance, straining and sometimes pain (dysuria)
- urinary retention due to incomplete emptying of the bladder
- repeated urinary tract infections (UTIs – urethritis and/or cystitis)
Other signs and symptoms that may be due to the stricture itself or causative pathology may include :
- frequent urination
- pelvic and/or lower abdominal pain
- urinary incontinence
- blood in the semen (hematospermia)
- blood in urine (hematuria)
- changes in urine stream – slow, weak and spray
- post-micturition dribble – dribbling after passing urine
- weak ejaculation
The presence and severity of any of the symptoms may vary depending on the degree of the narrowing.
Causes of a Narrow Urethra
A urethral stricture may be congenital (present from birth) or acquired (occurs during the course of life). Inflammation of the urethra may occur for number of reasons and this can lead to urethral scarring – formation of scar tissue in the wall of urethra. With congenital causes, the stricture is more likely due to an anatomical defects.
The following causes may sometimes lead to urethral strictures as a result of persistent urtheritis (inflammation of the urethra) or damage to the urethral wall. It does not occur in every case and overall a urethral stricture is an uncommon pathology.
- Mechanical trauma during catheterization or cystoscopy
- Damage due to passing kidney stones
- Radiation therapy
- Injury from a fall, blow or chemicals that enter the urethra
- Prostate surgery, circumcision
- Urinary tract infections (UTIs)
- Sexually transmitted infections (STIs)