What is Urinary Retention?
Urinary retention is the inability to empty the bladder completely. Urinary retention can vary in onset and severity. Acute urinary retention is a sudden, immediate, and complete inability to urinate, which requires immediate medical attention. Chronic urinary retention is a condition that develops gradually in which an individual is able to expel some but not all urine.
Urinary Retention Symptoms
Symptoms of urinary retention vary according to type and require different levels of medical attention.
Symptoms of Acute Urinary Retention include:
- Complete inability to urinate*
- Increased urinary urgency
- Painful urination
- Pain, pressure or discomfort in the lower abdomen
*Immediate medical attention is required
Symptoms of Chronic Urinary Retention include:
- Increased urinary frequency
- Urinary hesitation (delay at the onset of urination)
- A weak or inconsistent urinary stream
- Increased urinary urgency, sometimes immediately following urination
- Pain, pressure or discomfort in the lower abdomen
Secondary complications of urinary retention include:
- Urinary Tract Infections (UTIs)
- Bladder damage
- Kidney damage
- Urinary incontinence, particularly as a complication of surgery
Urinary Retention Causes
Urinary retention can result from problems in any of the urinary tract organs responsible for removing urine from the body. These include the bladder, the urethra, the bladder neck (internal sphincter), and the pelvic floor (external sphincter).
The bladder is a hollow, balloon-shaped organ that stores urine, a liquid waste product that is made by the kidneys as they filter waste from blood. As the bladder fills with urine, the urine applies pressure to the pelvic nerves, which signal to the brain that it is time for the body to expel the urine via urination.
The urethra is the tube through which urine is expelled. In women, it is located above the vagina. In men, it is located inside the penile shaft, and serves the dual purpose of expelling both semen and urine.
The bladder neck, or internal sphincter, is a muscle located at the junction of the bladder and the urethra that acts a wall to hold urine in the bladder.
The pelvic floor, or external sphincter, is a system of muscles that support the urethra.
When the bladder fills and the nerves signal to the brain that it is time for the body to urinate, the brain signals the bladder wall to tighten while simultaneously signalling the internal and external sphincters to relax. The combination results in urination, the expulsion of urine from the body.
However, if there is a malfunction in any of the organs involved in urination, urinary retention may occur.
Primary causes of urinary retention include:
- Obstruction of the urethra, in which the flow of urine from the urethra is obstructed by a foreign object or medical condition. Possibilities for urethral obstruction include blockage from an enlarged prostate gland (prostatitis), malformations of the urethral structure, urethral narrowing (stricture), urinary tract stones, pelvic prolapse such as cystocele or rectocele, constipation, and certain tumors and cancers.
- Malfunction of the nerves that regulate urination, particularly the nerves in the bladder, which may result from traumatic injury such as vaginal childbirth, brain or spinal cord infections or injuries, congenital conditions such as spina bifida, neurological conditions such as multiple sclerosis or Parkinson’s Disease, heavy metal poisoning, stroke, or diabetes.
- Side effects from medications, including
- Antihistamines (allergy treatments)
- Anticholinergics/antispasmodics (muscle cramp and spasm treatments)
- Tricyclic antidepressants (anxiety, depression, and pain treatments)
- Decongestants (common over-the-counter cold and flue treatments, including ephedrine, pseudoephedrine, and phenylephrine)
- High blood pressure medications (nifedipine)
- Anti-seizure medications (carbamazepine)
- Muscle relaxants (cyclobenzaprine)
- Opioid analgesics
- Weakened bladder muscles or sphincters, which may not be able to fully contract or relax properly to expel urine from the bladder.
Urinary Retention Diagnosis
To diagnose Urinary Retention, the physician will begin by ruling out other problems that may be causing the symptoms. First, the physician will perform a pelvic exam, to rule out malformations of the genitals and abdomen.
Next, the physician may conduct a postvoid residual measurement test, which will assess the amount of urine that remains in the bladder after urination. This test may be conducted via ultrasound, to produce imagery of the bladder, or via catheterization, to withdraw and measure the remaining volume of liquid in the bladder.
If these tests are inconclusive or indicative of Urinary Retention, the physician may proceed by ordering a CT Scan or cystoscopy, a procedure in which a lighted scope is inserted through the urethra via a catheter for the purpose of examining the bladder. Urodynamic tests may also be conducted to assess how well the bladder and the urethra are storing or releasing urine. These tests measure urinary flow in terms of speed and volume (uroflowmetry) and pressure (pressure flow study). Video urodynamic tests may also be conducted via x-rays to provide imagery of urinary processes.
Electromyography may also be used to measure the electrical activity of the nerves associated with urinary processes. In this procedure, sensors are placed on the skin near the urethra to monitor nerve and muscle activity.
Urinary Retention Treatment
Urinary Retention is treated in four primary ways:
- Bladder drainage, in which a patient’s urine is drained through catheterization. Typically, the catheter is threaded through the urethra. In cases of urethral obstruction, the catheter is placed directly into the bladder through an incision in the lower abdomen.
- Urethral dilation, to increase the diameter of the urethra so that urine may flow faster and more freely from the bladder. The dilation is accomplished by inserting tubes or inflating small balloons attached to catheters inside the urethra. The placement of urethral stents may also aid in the opening and widening of the urethra.
- Medications, to shrink the prostate in men (dutasteride or finasteride) or to relax the bladder (alfuzosin, doxazosin, silodosin, tadalafil, tamsulosin, or terazosin).
- Surgery, to remove or repair obstructions to the urethra, including prostate surgery to remove or reduce an enlarged prostate gland; internal urethrotomy, to open a blockage or widen a stricture in the urethra; cystocele or rectocele surgery to correct pelvic prolapse in women; or the removal of tumors or cancerous tissue.