Urinary retention

Disease Description (Causes and Symptoms)

• Definition: Urinary retention is a condition in which no urine is expelled from the bladder despite attempting to urinate, or urination is extremely difficult, leaving a large amount of residual urine. The normal bladder capacity is approximately 450–500 mL.
• Main pathophysiology:
  • Occurs due to either or both outflow obstruction (urethral or bladder outlet obstruction) and reduced bladder contractility (abnormal nerve or muscle function of the bladder). Prolonged retention may lead to bladder overdistension, bladder muscle damage, urinary tract infection, and damage to the upper urinary tract (kidneys).
• Main causes:
  • Mechanical obstruction: benign prostatic hyperplasia (BPH), urethral stricture, stones, tumors
  • Neurogenic causes: spinal cord injury, diabetic neuropathy, Parkinson’s disease, etc.
  • Drug-induced: antihistamines, some antidepressants and anticholinergic drugs, sympathomimetic drugs, anesthetics, etc.
  • Immediately after surgery, in hospitalized patients, in older adults, etc.
• Main symptoms:
  • Sudden inability to urinate, distension in the lower abdomen (suprapubic area), severe lower abdominal pain, straining with little or no urine output, a sensation of incomplete emptying, and sometimes nausea, vomiting, and tachycardia due to bladder overdistension

Treatment Methods

• Emergency treatment (highest priority):
  • Immediate insertion of a urethral catheter (if possible), or percutaneous suprapubic bladder catheterization through the upper abdomen if urethral access is not possible or there is obstruction.
  • After bladder decompression by catheterization, monitor vital signs, urine output (with caution for excessive diuresis), and electrolytes.
• Medication treatment:
  • When caused by benign prostatic hyperplasia: alpha blockers (such as tamsulosin and alfuzosin) to reduce urethral resistance. 5-α-reductase inhibitors (such as finasteride) are used for long-term reduction of prostate size.
  • Reduced bladder contractility (selective): cholinergic agonists such as bethanechol may be used for limited indications, but their efficacy and use are limited by side effects.
  • Medications to relax the urethra or antibiotics targeted to the cause (when accompanied by a urinary tract infection).
• Non-drug treatment, procedures, and surgery:
  • Intermittent self-catheterization (intermittent catheter insertion) — standard management for neurogenic bladder.
  • Transurethral resection of the prostate (TURP) or other prostate decompression procedures for benign prostatic hyperplasia.
  • Correction of the cause of obstruction, such as urethral dilation, tumor resection, or stone removal.
  • For neurogenic causes, consider bladder training, electrical stimulation (sacral nerve stimulation), and, when necessary, bladder reconstruction.
• Precautions (during and after treatment):
  • The risk of urinary tract infection increases after catheter insertion — aseptic procedures and catheter care are necessary.
  • Rapid bladder decompression may cause temporary massive diuresis (post-obstructive diuresis), resulting in hypotension and electrolyte abnormalities — monitoring and fluid replacement are necessary.
  • Anticholinergic drugs may worsen urinary retention, so they should be reviewed and adjusted as needed.
  • Recurrence is highly likely if the underlying cause is not corrected.

Checkpoints Before an Outpatient Visit (Items to Bring and Things to Check)

• Items to bring:
  • A list of all medications currently being taken (including prescription drugs, over-the-counter medications, and herbal medicines)
  • A history of previous surgeries (particularly urinary tract, pelvic, and spinal surgeries) and major diseases (such as diabetes and neurological diseases)
  • Copies of recent test results (blood tests, kidney function tests, urinalysis and urine culture, bladder ultrasound, etc.)
  • Symptom diary: when symptoms began, number of attempts to urinate and success rate, degree of pain, changes in urine volume, and whether fever or chills are present
• Main items the doctor will check during the outpatient visit:
  • Symptoms when attempting to urinate (inability to urinate completely, small amounts of urine, pain, etc.)
  • Recent fever, chills, or back pain (suspected upper urinary tract infection or pyelonephritis)
  • Whether urinary incontinence (overflow incontinence) is present
• Signs requiring emergency care:
  • Complete inability to urinate accompanied by severe abdominal pain or persistent vomiting, fever or chills, altered consciousness, etc.

Examples of General Questions to Ask the Doctor

• "What do you think is causing these symptoms?"
• "What emergency measures and long-term treatment plan are needed right now?"
• "What are the side effects of the medication you plan to prescribe, and what interactions does it have with other medications?"
• "What is the prognosis? How likely is recurrence?"
• "Are there any particular precautions I should take regarding lifestyle or diet?"

Examples of Condition-Specific Questions

• If benign prostatic hyperplasia is suspected: "Between surgery (for example, TURP) and medication treatment, which option is more suitable for my situation? What are the risks and expected benefits of surgery?"
• If neurogenic bladder is suspected: "Is intermittent self-catheterization appropriate for me? How should I receive training in self-catheterization and prevent infections?"