Reasoning GP · Algorithm · 1-page summary
Dysuria in adults
For: adults with dysuria in primary care, face to face or remote. Not for: children under 16 (use a paediatric pathway). Men, pregnancy, catheters, haematuria and suspected STI change the pathway — see blocks 1–2. Use with the local antimicrobial guideline.
Core rule: dysuria is not always cystitis. Exclude sepsis, retention, torsion and NG12 haematuria first; send an MSU before antibiotics in men and pregnancy; and test for STIs when urethritis or sexual risk is plausible.
0Stop — emergency — before any history
- Systemically unwell — hypotensive, confused, hypoxic, unable to take oral treatment or deteriorating (urosepsis; assess with NEWS2/local sepsis pathway) → Same-day emergency hospital; critically unwell or high sepsis risk → 999
- Acute scrotal pain (suspected testicular torsion) → Immediate emergency urology / surgery. Do not wait for imaging.
- Obstructed infected system or severe loin pain / suspected stone; pregnancy with fever, loin pain or systemic symptoms; immunocompromised → Same-day
- While waiting: cultures and antibiotics per the receiving hospital pathway — do not delay emergency transfer.
1Triage by group — minimum investigation
| Who | Do |
|---|---|
| Woman <65, not pregnant | Classic symptoms ± dipstick per local policy; MSU usually unnecessary |
| Aged 65+ | No dipstick (local guidance). Assess clinically; MSU if UTI suspected |
| Man · pregnancy | Pre-treatment MSU; a negative dipstick does not exclude UTI. Men: assess for prostatitis and STI |
| Catheter | No dipstick; culture only if symptomatic. Consider changing a catheter in place >7 days, without delaying antibiotics |
| Possible urethritis | First-void urine NAAT for chlamydia/gonorrhoea |
2Screen — one row is enough
- Aged 45+, visible haematuria unexplained without UTI, or persisting/recurring after successful UTI treatment → Suspected cancer pathway (NG12)
- Aged 60+, unexplained non-visible haematuria with dysuria or raised white cell count → Suspected cancer pathway
- Unable to void, palpable bladder (retention) → Same-day decompression; ED/urology if unable to catheterise, AKI, sepsis, clot retention, neurological features
- Man: fever, perineal pain, tender prostate (acute prostatitis) → Same-day hospital if unwell, in retention, abscess suspected or not improving 48 h after starting the antibiotic
- Genital ulcers / vesicles → HSV PCR swab; start aciclovir without waiting; GUM per local pathway. Cannot pass urine → Same-day
3Assess
☐ Temperature, pulse, BP, RR, confusion ☐ Suprapubic vs loin pain, palpable bladder ☐ Vaginal or urethral discharge, itch, dryness ☐ Sexual history, pregnancy possibility, catheter, drugs ☐ MSU before antibiotics: men, pregnancy, pyelonephritis, recurrent UTI, treatment failure
Prostatitis: gentle DRE only, no prostate massage. Renal USS only if obstruction/stone, recurrent or atypical infection, persistent haematuria or no improvement in 48 h.
4Classify — only if the screen is negative
- Cystitis — dysuria + frequency + urgency ± suprapubic pain. Leucocytes + nitrites (non-pregnant woman <65) → treat empirically.
- Urethritis / STI — dysuria alone, discharge, sexual risk → NAAT; GUM. Leucocytes are positive in both.
- Pyelonephritis — fever, loin pain → MSU, oral antibiotic if well; reassess if not improving in 48 h.
- Vaginal causes — itch, discharge (candida, BV, trichomonas); post-menopausal dryness → vaginal oestrogen.
- Uncertain or cultures negative — think STI, vaginitis, bladder pain syndrome. No repeated antibiotics; name who reviews.
5Treat today — doses: NICE/SPC, BNF, local formulary
- Woman, not pregnant: nitrofurantoin 100 mg MR BD 3 days (eGFR ≥45); or pivmecillinam, or trimethoprim 200 mg BD 3 days (check resistance).
- Man: trimethoprim 200 mg BD or nitrofurantoin (no prostate involvement) for 7 days. Prostatitis: 14 days, then review; fluoroquinolone only when others are inappropriate (MHRA).
- Pregnancy: nitrofurantoin 100 mg MR BD 7 days (avoid at term); then amoxicillin (if sensitive) or cefalexin per culture. No trimethoprim in the first trimester.
- Pyelonephritis, well: cefalexin 500 mg BD–TDS 7–10 days. Never nitrofurantoin, pivmecillinam or fosfomycin.
6Refer routinely
- Man with recurrent UTI (≥2 in 6 months or ≥3 in 12) or structural cause, suspected stricture → urology.
- Recurrent UTI in women: culture-confirm; NG112 ladder (self-care → vaginal oestrogen → trigger dose → methenamine or daily prophylaxis). Imaging/urology if atypical, haematuria, obstruction or stones.
- STI → GUM per local pathway, with partner notification. Chronic dysuria, negative cultures → urology/gynaecology.
7Never reassure by
- A "UTI" that explains visible haematuria — recheck after treatment.
- A negative dipstick in a man or in pregnancy.
- Treating "UTI" in a sexually active young man without an STI NAAT.
- A positive dipstick or MSU in a catheterised or asymptomatic patient.
- Sudden scrotal pain labelled as infection — torsion first.
- Repeated antibiotics while cultures stay negative.
8Safety-net — say it, then document it
999 “Call 999 if you become very unwell, confused or collapse.” Same day: “Contact us today if symptoms worsen quickly, are not starting to improve within 48 hours, vomiting stops you taking the tablets, or you get loin pain, blood in your urine or cannot pass urine.”
Nitrofurantoin: report new cough, breathlessness, chest pain, jaundice, dark urine or pale stools. Fluoroquinolone: stop and seek urgent advice at the first serious reaction (tendon, muscle, joint, nerve, mood).
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies
Observations normal; not systemically unwell
MSU sent where required; STI tested if sexual risk
Haematuria plan set: recheck after treatment
Safety-net given; 48-hour review rule clear
Summary of the full Reasoning GP dysuria algorithm, which holds the detail, special situations and evidence. Sources: NICE NG109, NG110, NG111, NG112, NG113, NG12 (updated April 2026), NG23; MHRA; BASHH; local antimicrobial guideline. Clinical reference — follow local pathways and check doses: NICE/SPC, BNF.