Reasoning GP · Algorithm · 1-page summary
Mastalgia (breast pain)
For: breast pain in primary care, with or without a cyclical pattern. Not for: pregnancy or breastfeeding, which need a separate assessment pathway. A lump, skin or nipple change follows NICE NG12 (block 1).
Core rule: breast pain alone with a normal examination is very rarely cancer and needs no routine imaging. Examine both breasts, axillae and chest wall every time: a lump, skin or nipple change sets the pathway, not the pain.
0Stop — call 999 now — none for breast pain alone
- Breast abscess with sepsis — high fever, rigors, haemodynamic compromise or septic shock → 999
- Known or suspected breast cancer with suspected spinal cord compression, or a suspected pathological fracture with severe pain, deformity or neurovascular compromise → 999 / emergency
1Triage by examination — NICE NG12 (updated April 2026)
| Finding | Action |
|---|---|
| Lump, age 30+ | Unexplained, with or without pain → Suspected cancer referral |
| Lump, under 30 | Non-urgent referral; hard, fixed, enlarging or suspicious → Urgent |
| One nipple, 50+ | Discharge, retraction or other change → Suspected cancer referral |
| Skin or axilla | Skin change suggestive of cancer (any age), or unexplained axillary lump at 30+ → consider Suspected cancer referral |
| Pain only | Normal examination → manage in primary care; no imaging |
2Screen — one row is enough
- Mastitis with systemic illness, spreading cellulitis or suspected abscess → Same-day; abscess needs breast/ultrasound assessment and drainage, not repeat antibiotics.
- Non-lactational mastitis not improving at 48 h → reassess; persistent, recurrent or atypical → breast service (inflammatory cancer).
- Previous breast cancer + new persistent focal bone or back pain, neurological or systemic features → Same-day acute oncology contact.
- Spontaneous one-sided bloody or serous discharge → local breast pathway (suspected cancer if 50+). Hard supraclavicular nodes → Suspected cancer referral
- Pregnancy possible → urine hCG. Galactorrhoea or menstrual disturbance → prolactin and TSH.
3Assess — with a chaperone offered
☐ Inspect sitting (arms down, then raised) and lying ☐ Palpate 4 quadrants, axillary tail, subareolar; axillae and supraclavicular nodes ☐ Press costochondral junctions; check shoulder and spine ☐ Bra fit ☐ Medicines: HRT, OCP, SSRIs, antipsychotics, spironolactone, digoxin
Do not: request mammography for pain alone, routinely express the nipple, order hormone panels or routine bloods, or delay referral for imaging.
4Classify — only if the screen is negative
- Cyclical — bilateral, diffuse, upper outer; builds 1–2 weeks before a period and eases with it → primary care.
- Non-cyclical — one-sided, focal, sharp or burning (duct ectasia, cyst, Mondor's) → review; reconsider chest wall.
- Chest wall — reproduced by pressing costochondral junctions, not the breast → manage as MSK.
- Drug-induced — timing fits a medicine → shared medication review.
- Post-menopausal or persistent focal pain, normal exam → review; consider non-urgent breast clinic.
- Uncertain — pain diary (Cardiff chart) for up to two cycles; refer any uncertain finding on judgement.
5Treat today — doses: NICE/SPC, BNF, local formulary
- All benign types: explanation after a normal exam, well-fitting supportive bra, simple analgesia.
- Topical NSAID (e.g. diclofenac gel) — first drug step, preferred over oral NSAIDs.
- Chest wall: topical NSAID or oral ibuprofen with food (cautions) + heat; consider steroid injection if persistent; physio if recurrent.
- Drug-induced: do not change effective HRT, contraception, antidepressant or antipsychotic without shared decision; endocrine therapy only with specialist.
6Refer routinely · review
- Severe cyclical pain affecting life or sleep, no response to 3 months of first-line treatment → breast clinic.
- Persistent, unexplained focal pain with normal exam → consider non-urgent breast clinic. Symptomatic macrocyst or recurrent cysts → breast clinic.
- Review: 2–4 weeks if new medicine · 6–8 weeks (2 cycles) · 3 months: discharge or refer · consider stopping at 6 months.
7Never reassure by — or do
- Focusing on the pain and missing a concurrent lump.
- The presence of pain: a lump at 30+ meets NG12 with or without pain.
- Pain location alone — it does not rule malignancy in or out.
- Repeated antibiotics for a suspected abscess or mastitis not settling.
- Starting tamoxifen, danazol or bromocriptine in primary care.
- Routinely recommending evening primrose oil, vitamin E or B6.
8Safety-net — say it, then document it
999 “Call 999 if you have a hot, painful breast with a high fever, shivering, or you feel faint or very unwell.” Same day “Contact us the same day if you find a new lump or new focal pain, dimpling or orange-peel skin, a nipple turning in, or bloodstained discharge from one nipple.”
Return if the pain becomes one-sided, focal and persistent, or loses its link to periods; or weight loss or bone pain. Give breast-awareness advice; NHS breast screening from 50.
✓Safe to manage in primary care only if — all five, documented
No block 0–2 feature; no NG12 criterion met
Breasts, axillae, nodes and chest wall examined; chaperone offered
Pregnancy and medicines considered
Subtype named; review booked (6–8 weeks, 3 months)
Safety-net given; screening up to date
Summary of the full Reasoning GP mastalgia algorithm, which holds the detail, examination, investigations and evidence. Sources: NICE NG12 (updated April 2026) and its breast pain evidence review; Association of Breast Surgery guidelines; NHS Breast Screening Programme. Clinical reference — follow local breast pathways and check doses: NICE/SPC, BNF.