Bladder distension occurs when the bladder stretches beyond its normal capacity due to an inability to fully empty. This causes the organ to become abnormally full, leading to discomfort and potential complications from urine buildup.
Causes of Bladder Distension
Bladder distension can arise from various factors that impede normal urine flow or the bladder’s ability to contract.
Physical Obstructions
One common category involves physical obstructions that block the urethra, the tube carrying urine out of the body. In men, an enlarged prostate (benign prostatic hyperplasia or BPH) can compress the urethra, making urination difficult. Other blockages include bladder stones, which are hard mineral deposits, or tumors. Urethral strictures, which are narrowings of the urethra, can also restrict urine passage.
Nerve Damage
Conditions affecting the nerves that control bladder function represent another cause. Neurological disorders like diabetes, spinal cord injuries, or multiple sclerosis can disrupt signals between the brain and bladder. This interference prevents the bladder muscle from contracting properly or the sphincter muscles from relaxing, leading to incomplete emptying.
Medications
Certain medications contribute to urinary retention and bladder distension. Antidepressants, some antihistamines, and opioids can weaken bladder contractions or increase sphincter tone, making urination challenging, leading to urine buildup.
Weak Bladder Muscle
In some instances, the bladder muscle (detrusor muscle) may become too weak to contract effectively. This weakness can stem from prolonged overstretching due to chronic retention, aging, or certain muscle disorders. A weakened detrusor muscle struggles to push urine out, resulting in incomplete emptying and a constantly full bladder.
Associated Symptoms and Signs
The experience of bladder distension varies depending on whether the condition is acute or chronic.
Acute Distension
Acute bladder distension develops suddenly and is typically characterized by sharp, intense lower abdominal pain. Individuals often report a sudden, complete inability to urinate despite a strong urge. This rapid onset of severe pain and urinary blockage usually signals a medical emergency, requiring immediate attention.
Chronic Distension
Chronic bladder distension develops gradually, and its symptoms may be more subtle. People might experience a frequent urge to urinate but find it difficult to initiate a stream. The stream itself may be weak, hesitant, or interrupted. A feeling that the bladder is never completely empty after urination is also common.
Overflow incontinence, where urine leaks involuntarily, can occur when the bladder becomes so full that pressure forces small amounts of urine past the sphincter. This happens even without a strong urge to urinate. A doctor performing a physical examination might feel a firm, rounded lump in the lower abdomen, which is the distended bladder. These persistent symptoms can significantly affect daily life.
Diagnostic Procedures
Confirming bladder distension and identifying its underlying cause involves a series of diagnostic procedures.
A physical examination is often the initial step, where a healthcare provider gently palpates the lower abdomen. This manual check helps determine if the bladder feels full or firm, indicating the presence of retained urine.
A bladder scan is a common, non-invasive procedure used to measure the volume of urine in the bladder. This portable ultrasound device provides an estimate of the post-void residual (PVR) volume, the amount of urine remaining after urination. A high PVR volume confirms incomplete emptying and bladder distension.
If the cause is not immediately clear, further investigations may be necessary. These include:
A kidney ultrasound to check for urine backflow into the kidneys.
A cystoscopy, which involves inserting a thin, flexible tube with a camera into the urethra to visualize the bladder’s interior and identify blockages.
Urodynamic studies, which measure bladder pressure and urine flow to assess bladder function.
Medical Interventions and Management
The immediate priority in managing bladder distension, especially in acute cases, involves draining the accumulated urine. This process, known as bladder decompression, is most commonly achieved by inserting a urinary catheter. The catheter, a thin, flexible tube, is guided through the urethra into the bladder, allowing the trapped urine to flow out and providing immediate relief from pain and pressure. This initial step helps to prevent further damage to the bladder and kidneys.
Long-term management focuses on addressing the specific underlying cause.
Enlarged Prostate: Medications like alpha-blockers or 5-alpha-reductase inhibitors may be prescribed to relax prostate muscles or shrink the gland. Surgical procedures, such as transurethral resection of the prostate (TURP), might be considered for severe obstruction.
Urethral Strictures: Surgical widening or reconstruction may be performed.
Nerve Damage: Strategies might include nerve stimulation techniques or medications to improve bladder function.
Medication Side Effects: Adjusting dosages or switching to alternative drugs can alleviate the issue.
Weak Bladder Muscle: Supportive strategies become important. These include timed voiding, where individuals attempt to urinate at regular intervals to prevent overfilling. For chronic conditions where the bladder cannot empty fully, intermittent self-catheterization may be taught. This involves the individual periodically inserting a catheter to drain their own bladder, providing consistent emptying and reducing complication risk.