Causes by Pattern
| Pattern | Likely Cause |
|---|---|
| Frequent + burning + urgency | Urinary tract infection (cystitis) |
| Frequent + large volumes + thirst | Diabetes mellitus, diabetes insipidus |
| Urgent + frequency + no pain | Overactive bladder (OAB) |
| Hesitancy + weak stream + frequency (men) | Benign prostatic hyperplasia (BPH) |
| Nocturia (night-time only) | Heart failure, CKD, sleep apnoea, excess evening fluid |
| Frequent + blood in urine | Bladder cancer (urgent referral), UTI, stones |
| Frequency + loin pain | Kidney stones, pyelonephritis |
Investigations
- Urine dipstick and MSU (midstream urine culture): rule out UTI
- Glucose and HbA1c: exclude diabetes
- PSA (men >50): screen for prostate pathology
- Post-void residual ultrasound: detects urinary retention
- Bladder diary (3 days), records times, volumes, urgency, essential for OAB assessment
- Cystoscopy: if haematuria or symptoms don't respond to treatment
Bladder DiaryBefore seeing a specialist, keep a bladder diary for 3 days: record every time you drink and urinate (with volume), any urgency or leakage. This is the most valuable information for assessing OAB and choosing treatment.
What is overactive bladder?
OAB is characterised by urgency (sudden compelling desire to urinate), with or without urgency incontinence, usually with frequency and nocturia. Treated with bladder training, pelvic floor exercises, anticholinergics, or mirabegron.
What causes nocturia (waking at night to urinate)?
Common causes: diuretic medication timing, excessive evening fluid intake, OAB, heart failure (fluid shifts on lying), CKD, BPH (men), sleep apnoea, and diabetes. Keep a fluid diary to identify timing patterns.
How is UTI treated?
Simple cystitis: nitrofurantoin 100mg MR twice daily for 5 days (women) or 7 days (men). Trimethoprim 200mg twice daily for 7 days is an alternative. Pyelonephritis (kidney infection): co-amoxiclav 7–14 days; IV antibiotics if unwell.
Can reducing fluid intake help frequent urination?
Only if intake is excessive. Reducing caffeine and alcohol (bladder irritants) helps OAB. Restricting total fluid intake to below 1.5L/day actually worsens OAB: keep normal hydration (1.5–2L/day) but reduce bladder irritants.
Related reading
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Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.