Urination disorders

Main disorders and their mechanisms

Urination disorders are extremely diverse, but in clinical practice, several basic syndromes are most commonly distinguished:

• Strangury (Strangury) — the act of urination is difficult and accompanied by sharp spastic pain. The pathogenetic basis is a pronounced spasm of the smooth muscle layer of the bladder wall, localized mainly in the area of its neck.
• Pollakiuria (Pollakiuria) — pathologically frequent urination in which urine is excreted in very small portions. This occurs due to hypersensitivity of nerve endings in the mucous membrane: even a minimal amount of fluid irritates the receptors and provokes a strong urge.

Pain syndrome: etiology and features

Patients most often describe pain during urination as severe burning. The main cause is an inflammatory process or direct irritation of the mucous membrane of the urethra and bladder. Among frequent triggers: passage of urinary calculi, acute prostatitis, tumor formations, or foreign bodies.

The localization and character of pain strongly depend on the patient's sex and age:

• In men pain usually radiates to the glans penis or is felt somewhat more proximally.
• In women there is a sensation of pressure or discomfort inside the urethra. The burning sensation is often associated with the excreted urine contacting the damaged urethral mucosa or inflamed tissues of the labia majora.
• During the postmenopausal period pain may occur due to a natural decrease in estrogen levels, leading to thinning and atrophy of the epithelium of the urethra and bladder base.

Urinary incontinence

Involuntary loss of urine indicates functional or anatomical defects of the bladder, adjacent structures, or their innervation. Several pathogenetic variants are distinguished:

1. Urge incontinence (Urge incontinence) — occurs due to excessively strong, uncontrolled contraction of the detrusor (the muscle that expels urine).
2. Stress incontinence — urine leakage occurs against the background of increased intra-abdominal pressure during physical exertion.
3. Paradoxical ischuria (Ischuria paradoxa) — a severe condition combining complete urinary retention with incontinence. The bladder overflows due to obstruction, intravesical pressure rises critically, and literally "forces" fluid through the obstruction in small drops.
4. Functional/drug-induced — develops as a side effect of therapy or in severely cachectic patients.

Enuresis (Enuresis) — nocturnal enuresis — is singled out separately. In pediatrics, it is more common in boys. The main cause is immaturity of neural regulatory mechanisms, provided there is a complete absence of anatomical anomalies. If the problem returns after a long "dry" period, secondary enuresis is diagnosed.

Topical differential diagnosis

Careful history taking allows one to suspect the level of urinary tract lesion:

• Time of pain onset: if sharp pain appears at the very beginning of urination, this is a typical sign of acute urethritis. If pain is maximal at the end of the act, acute cystitis should be suspected.
• Classic lower tract inflammation syndrome: includes a triad — pollakiuria, pain, and urgency.
• Vesicorectal fistulas: a severe complication (e.g., in advanced prostate cancer). Clinically manifested by pneumaturia (passage of gas through the urethra), fecal matter in the urine, and passage of urine through the rectum.

Class and exam questions

What else to study on this topic

• Pathophysiology of paradoxical ischuria and methods for its resolution
• Differential diagnosis of types of urinary incontinence
• Specific symptoms of vesicointestinal fistulas
• Age-related changes in the urothelium in postmenopausal women
• Clinical presentation and criteria for lower urinary tract inflammation syndrome

Other topics in the "Urinary System" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.