TL;DR: Key Takeaways
- NHS lists 5 main symptom categories — a useful starting point but not exhaustive
- GPs use the Glasgow 7-point checklist; a score of 3+ triggers urgent referral
- Roughly 1 in 5 melanomas are amelanotic (pink or skin-coloured) and easily missed visually
- Subungual, acral and rare melanoma subtypes are under-represented in standard guidance
- AI screening + monthly photo monitoring catches changes the eye doesn't
What the NHS Website Tells You
The NHS's public skin cancer pages cover the essentials clearly. They list five main signs to look out for: a new mole or a change to an existing mole; a sore or spot that hasn't healed after four weeks; a lump that's growing; a rough, scaly or red patch; and any unusual change in skin colour or texture. This is solid baseline guidance — and if any of these apply to you, book a GP appointment.
What the NHS pages don't go into much detail about is the variation: how melanoma can appear in forms that don't match the textbook image. That's the gap this guide fills — not in opposition to NHS guidance, but as a layer of detail on top.
The ABCDE Rule (Used Globally)
- A — Asymmetry: one half doesn't match the other
- B — Border: irregular, ragged or notched edges
- C — Colour: multiple colours within a single mole (brown, black, red, white)
- D — Diameter: typically larger than 6mm, but melanomas can be smaller
- E — Evolving: any change in size, shape, colour, elevation or new symptoms
Read our full ABCDE guide for visual examples.
The 7-Point Checklist (What UK GPs Actually Use)
NICE guidance recommends UK GPs use the Glasgow 7-point weighted checklist when assessing suspicious lesions:
- Major features (2 points each): change in size, irregular shape, irregular colour
- Minor features (1 point each): diameter ≥7mm, inflammation, oozing/crusting, change in sensation (itch, tingle)
- Total of 3 or more = urgent suspected cancer (2-week-wait) referral
- Strong clinical suspicion = refer regardless of score
If your GP examines a spot and you're unsure whether they applied this — politely ask. It signals you've done your homework and helps anchor the conversation.
Add a screening layer between you and the GP
ScanSkinAI is UKCA Class I certified and free for your first scan. Use it as a second opinion alongside NHS guidance.
Symptoms That Are Easier to Miss
Amelanotic melanoma (pink or skin-coloured)
About 1 in 5 melanomas have little or no pigment. They appear pink, red or skin-coloured and are routinely mistaken for spots, scars or benign cysts — by patients and sometimes by clinicians. Read our dedicated guide on amelanotic melanoma.
Acral lentiginous melanoma (palms, soles, nails)
Found on palms, soles, fingernails or toenails. Often appears as a dark streak under the nail or a flat brown patch on the sole. This subtype disproportionately affects darker skin tones and is frequently diagnosed late — see our melanoma on nails guide and our overview of skin checks for people of colour.
Subungual melanoma (under the nail)
Presents as a brown or black streak running the length of the nail (Hutchinson's sign extends pigment into the cuticle). Easy to dismiss as a minor injury or nail polish stain. Any new or expanding nail streak deserves a GP review — covered in depth in our subungual melanoma guide.
Nodular melanoma (rapid-growth)
Doesn't follow ABCDE. Appears as a firm, raised, often symmetrical lump that grows quickly — over weeks rather than months. EFG (Elevated, Firm, Growing) is a complementary rule for spotting these.
Why Visual Exam Alone Isn't Enough
Even with dermatoscopy, the most experienced UK dermatologists report missing a small but meaningful percentage of melanomas at first visual exam. AI screening tools trained on millions of images can detect subtle pattern signals that the human eye doesn't reliably register — particularly subtle asymmetry, micro-colour variation and structural irregularities. Our AI vs dermatologist comparison goes into the published evidence. This isn't anti-NHS — it's adding a tool to the kit.
The most defensible approach for UK readers in 2026: NHS guidance + a structured monthly self-exam + AI screening + GP review for anything flagged or persistent. For non-melanoma signs, our non-healing sore guide covers BCC and SCC presentations.
When to Push for a 2-Week-Wait Referral
- Any new mole appearing after age 30
- Existing mole with two or more ABCDE changes
- A spot that's bled, ulcerated or non-healing for more than 4 weeks
- An 'ugly duckling' — any mole obviously different from your others
- AI screening result of moderate or high concern
- Family history of melanoma in first-degree relative
For the full pathway after referral, see our NHS mole check guide.