Reasoning GP · Algorithm · 1-page summary
Foot pain in adults
For: adults with heel, midfoot, forefoot or toe pain in primary care, with or without diabetes. Not for: children (use the limping child algorithm); pain centred on the ankle (use the ankle pain algorithm).
Core rule: in diabetes, a warm, swollen or ulcerated foot is infection or Charcot until proven otherwise — Charcot is often not very painful. Refer via the diabetic-foot pathway; never treat it as simple mechanical pain.
0Stop — call 999 now
- Open fracture, dislocation or gross deformity, crush injury, major trauma or compartment syndrome → 999
- Acute limb ischaemia: sudden pain, pallor, cold, numb, weak or pulseless (may be incomplete) → immediate vascular review; 999 if limb threatened, severe pain, neurological deficit or unstable.
- Necrotising fasciitis: severe or disproportionate pain with systemic illness, bullae, discolouration or rapid spread → 999; normal markers do not exclude it.
- Diabetic foot with sepsis, severe ischaemia, gangrene or suspected deep infection → 999 / immediate hospital referral (NG19).
1Triage — diabetes or peripheral arterial disease first
| Finding | Action |
|---|---|
| Diabetes: hot, red, swollen foot | Suspected Charcot → foot service ≤1 working day; non-weight-bearing |
| Diabetes: other active problem | Ulcer, blister, skin break, colour change, unexplained pain → foot service ≤1 working day |
| PAD: rest pain, tissue loss | Vascular; emergency if critical ischaemia, gangrene or osteomyelitis |
| None of the above | Localise by zone (block 4); mostly clinical |
2Screen — serious causes
- Acutely painful, restricted, swollen joint (fever, bloods may be normal) → Same-day hospital + aspiration; never delay antibiotics if septic.
- Achilles rupture: Thompson's test — no plantarflexion → Same-day assessment + immobilisation.
- Stress fracture at a high-risk site (navicular, Jones/5th metatarsal) or Lisfranc injury → Same-day orthopaedics; stop loading.
- Unilateral calf swelling or pain: Wells likely → USS ≤4 h, or D-dimer + interim anticoagulation + USS ≤24 h.
- Persistent focal bone or night pain, mass → X-ray; suggests sarcoma → consider suspected cancer pathway. Growing lump → consider USS ≤2 weeks.
- New persistent synovitis → Urgent rheumatology; do not wait for bloods.
3Assess
☐ Both feet, standing, gait ☐ Pulses, 10 g monofilament, vibration ☐ Diabetes: temperature difference, ulcer ☐ Thompson's test ☐ Urate in suspected gout ☐ CRP, ESR, FBC if septic or inflammatory ☐ HbA1c if neuropathy
Not routine: X-ray or MRI for plantar fasciitis, HLA-B27, D-dimer outside Wells.
4Classify — only if blocks 0–2 are negative
- Plantar fasciitis — first-step medial heel pain, worse after rest, tender medial calcaneal tubercle.
- Achilles tendinopathy — mid-portion or insertional, Thompson's normal. Ask about fluoroquinolones.
- Midfoot — tibialis posterior (medial arch pain, progressive flat foot), midfoot OA, navicular stress fracture.
- Forefoot — Morton's neuroma (3rd–4th web-space burning), metatarsalgia, stress fracture.
- Gout — acute hot, red, swollen 1st MTP. Inflammatory arthritis — dactylitis, nail changes, symmetric MTP synovitis.
- Uncertain — not better after 4–6 weeks of first-line care → re-examine, X-ray; MRI via local MSK pathway.
5Treat today — doses: NICE/SPC, BNF, local formulary
- Plantar fasciitis: reduce high-impact load (not rest), calf and plantar-fascia stretches, heel cup, cushioned shoes. Injection only if persistent, after discussing risks.
- Achilles tendinopathy: reduce aggravating load; progressive tendon-loading physiotherapy. No steroid injection into or around the Achilles.
- Acute gout (sepsis excluded): offer NSAID, colchicine or short oral steroid by renal function, CV/GI risk, interactions. Keep low-dose aspirin.
- Diabetes: daily foot inspection, never barefoot, report any skin break the same day; stop smoking.
6Refer routinely and review
- Physiotherapy / podiatry: plantar fasciitis, tendinopathy, tibialis posterior; orthotics, nails, callus.
- Orthopaedics/MSK: plantar fasciitis or hallux valgus/rigidus failing 6 months' conservative care; Morton's not settling; tarsal tunnel.
- Rheumatology: recurrent gout with renal impairment; reactive arthritis >3 months. Vascular: suspected PAD, non-healing ulcer.
- Review: gout 1–2 weeks (ULT 2–4 weeks after the flare); plantar fasciitis 4–6 weeks; diabetes annual foot risk check.
7Never reassure by
- Little pain in a hot, swollen diabetic foot — Charcot is often not very painful.
- No fever or normal bloods in a hot, swollen joint.
- A normal X-ray (stress fracture, early malignancy).
- No palpable gap — do Thompson's test for Achilles rupture.
- Normal capillary refill, or a normal ABPI in diabetes (may be falsely high).
- A normal urate during a gout flare.
8Safety-net — say it, then document it
999 “Call 999 if your foot suddenly becomes very painful and pale, cold, numb or weak; if redness or swelling spreads fast with blistering, severe pain and feeling very unwell; or after a crush injury.”
Same day: “If you have diabetes or circulation problems, report any new break in the skin, blister, swelling, redness, colour change or worsening pain the same day — contact us or NHS 111. Go to A&E today for a hot, swollen, painful joint, even without a fever. Come back if not improving in 4–6 weeks.”
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies
Diabetes/PAD status, pulses and sensation recorded
Thompson's test when heel pain or lost push-off
Diagnosis named, or uncertainty → imaging or specialist
Review date and safety-net given and documented
Summary of the full Reasoning GP foot pain algorithm, which holds the history, examination tests, treatment ladders and evidence. Sources: NICE NG19 (diabetic foot), NG219 (gout), NG12 (suspected cancer, updated April 2026), NG158 (VTE diagnosis), NG100 (rheumatoid arthritis), NG226 (osteoarthritis). Clinical reference — follow local pathways and check doses: NICE/SPC, BNF.