What is the cause of increased urinary frequency and general malaise in a patient with no other symptoms?

Differential Diagnosis: Increased Urinary Frequency with General Malaise

The most likely causes in a patient with increased urinary frequency and general malaise without other symptoms are urinary tract infection (UTI), overactive bladder (OAB), or diabetes-related bladder dysfunction—with UTI being the most critical to rule out first given its potential for progression to serious complications. 1, 2

Immediate Diagnostic Priorities

Rule Out Urinary Tract Infection First

• Obtain urinalysis and urine culture immediately to exclude UTI, as this is the most common treatable cause of increased frequency with systemic symptoms like malaise 1, 2, 3
• The absence of dysuria does NOT exclude UTI—many patients, particularly elderly or diabetic individuals, present with atypical symptoms including only frequency and general malaise 1
• A negative urinalysis for white blood cells and negative leukocyte esterase dipstick effectively excludes UTI, though rare exceptions exist in neutropenic patients 1
• E. coli causes approximately 75% of UTIs, with other common organisms including Enterococcus faecalis, Proteus mirabilis, and Klebsiella 1

Assess for Overactive Bladder

• If UTI is excluded and the patient reports bothersome daytime and nighttime urinary frequency with urgency (with or without incontinence), consider OAB as the diagnosis 2
• The hallmark symptom of OAB is urgency—a sudden, compelling desire to void that is difficult to defer 2
• OAB typically presents with more than seven micturition episodes during waking hours, though this varies with fluid intake and sleep patterns 2
• Critical distinction: OAB should NOT be associated with pain—if pelvic, bladder, or scrotal pain is present, consider Painful Bladder Syndrome/Interstitial Cystitis instead 3

Measure Post-Void Residual (PVR)

• Obtain PVR measurement (ideally by portable ultrasound) to rule out overflow incontinence 1, 4
• An elevated PVR >250-300 mL suggests overflow incontinence from urinary retention, which can present with frequency and "incontinence" that is actually overflow 4
• This is particularly important before considering any antimuscarinic medications, as these will worsen retention 4

Secondary Considerations Based on Patient Context

Diabetes-Related Bladder Dysfunction

• If the patient has diabetes, consider diabetic cystopathy, which presents with frequency, urgency, nocturia, and incomplete emptying 1
• Diabetic patients have increased susceptibility to UTIs due to altered immune function and urothelial changes 1
• Peak urinary flow rate and PVR measurement are particularly important in diabetic patients with lower urinary tract symptoms 1

Recurrent UTI Pattern

• If this represents recurrent infections (≥3 episodes in 12 months), imaging is generally NOT indicated unless there are risk factors for complicated UTI 1
• Risk factors requiring imaging include: rapid recurrence within 2 weeks of treatment, bacterial persistence despite treatment, history of stones, structural abnormalities, or immunosuppression 1

Diagnostic Algorithm

1. Urinalysis and culture → If positive, treat UTI appropriately 1, 2
2. If urinalysis negative → Measure PVR 4
   • If PVR >250-300 mL → Evaluate for causes of retention (obstruction, neurogenic bladder, medications) 4
   • If PVR normal → Assess for urgency symptoms 2
3. If urgency is present without pain → Diagnose OAB and consider voiding diary to document frequency patterns 2
4. If pain is present with frequency → Consider Painful Bladder Syndrome/Interstitial Cystitis 3
5. If diabetic → Evaluate for diabetic cystopathy with urodynamic studies if initial management unsuccessful 1

Critical Pitfalls to Avoid

• Do not assume all frequency is OAB—failure to check urinalysis can miss treatable UTI 2, 3
• Do not prescribe antimuscarinics without measuring PVR first—this can precipitate acute urinary retention in patients with overflow incontinence 4
• Do not dismiss atypical UTI presentations—elderly and diabetic patients often lack classic dysuria and may present only with frequency and malaise 1
• Do not treat asymptomatic bacteriuria—if the patient truly has no symptoms other than frequency, positive urine culture alone does not warrant treatment 1
• Do not order imaging for uncomplicated recurrent UTIs—imaging has low yield unless specific risk factors are present 1