GMC-Registered · UK skin cancer specialist
Dermatologist's quick take
- Most moles are completely harmless — but change is the universal warning sign
- A mole that bleeds, itches, or doesn't heal needs assessment within 4 weeks
- New moles after age 40 should be checked, even if they look benign
- Pigmented streaks on nails or moles under nails warrant urgent dermatology review
- Annual professional checks + monthly self-checks halve melanoma mortality
I'm Dr. Iwasa, and "should I worry about this mole?" is the single most common question I'm asked in clinic — by patients, friends, and even strangers at parties. The honest answer is: usually no, but sometimes yes, and the difference matters more than almost any other dermatology decision.
This guide gives you a clear set of red flags. If any apply to you, book a dermatologist this week. Between visits, use ScanSkinAI's AI mole check to track changes objectively.
The 9 warning signs
1. Recent change
Any change in size, shape, colour, or elevation in the past 3 months.
2. New mole after 40
Most benign moles appear before adulthood. New pigmented lesions in midlife deserve evaluation.
3. Bleeding or crusting
Spontaneous bleeding, oozing, or crusting that doesn't heal within 2 weeks.
4. Itch or pain
Persistent itching, tenderness, or burning in a single mole.
5. Non-healing bump
A pink or red bump that has been there for 4+ weeks and isn't healing.
6. Nail pigmentation
A dark streak under a fingernail or toenail, or pigment extending into the cuticle (Hutchinson's sign).
7. The ugly duckling
A mole that looks distinctly unlike your other moles — darker, lighter, larger, or differently shaped — is statistically more likely to be melanoma than a mole that fits your normal pattern.
8. Multiple colours within one mole
Brown, black, red, white, or blue patches within a single lesion. Healthy moles are usually one uniform shade. This corresponds to the "C" of the ABCDE rule.
9. Family or personal history
A first-degree relative with melanoma roughly doubles your risk. A personal history of melanoma means new moles need closer attention. People with 50+ moles or atypical naevi syndrome should see a dermatologist annually.
What dermatologists actually do
In clinic, I use a dermatoscope — a polarised magnifier that reveals patterns invisible to the naked eye. Most "scary-looking" moles turn out to be perfectly benign under dermoscopy. Conversely, some innocent-looking lesions reveal melanoma-specific features. This is why a 5-minute dermatologist visit beats months of internet anxiety.
What to bring to your dermatology appointment
- Photographs of the mole over time, with dates
- Family history of melanoma (parents, siblings)
- List of all medications, especially immunosuppressants
- Sun exposure history — childhood sunburns, tanning beds, outdoor work
- Any prior biopsies or skin cancers, including basal/squamous cell
Same-week dermatology referral if you have:
- A mole that has visibly changed in the past 4–8 weeks
- A non-healing skin lesion that bleeds repeatedly
- A new pigmented streak under a fingernail or toenail
- A pink/red bump growing over weeks (rule out nodular or amelanotic melanoma)
In the UK, ask your GP about the 2-week-wait suspected melanoma pathway.
How to monitor between visits
Photograph any concerning mole monthly, against the same background and lighting. A free AI mole check at ScanSkinAI applies ABCDE analysis automatically and stores dated photos for you. This evidence is what lets dermatologists make confident decisions — change over time is the strongest melanoma indicator.
For the underlying framework dermatologists use, see our guide to the ABCDE rule and how often you should get a skin check.
Get an instant AI mole assessment
60-second photo analysis with ABCDE scoring. Find out if your mole needs urgent review.
Frequently Asked Questions
Superficial spreading melanoma (most common) takes months to years. Nodular melanoma can grow rapidly — millimetres per month. If a mole has visibly changed in 4–8 weeks, see a dermatologist within 2 weeks.
Occasional itching from friction or dryness is normal. Persistent itch lasting weeks, especially in a single mole, warrants assessment.
Yes — trauma, shaving, or scratching can cause bleeding. A mole that bleeds spontaneously, repeatedly, or doesn't heal in 2 weeks should be examined.
Suspected melanoma triggers a 2-week-wait pathway in the UK. Routine referrals can take 6–18 weeks. If urgent features are present, your GP will fast-track you.
No. Excision is a clinical decision based on dermoscopy. Removing benign moles unnecessarily creates scars, costs money, and doesn't reduce melanoma risk.
No. Trauma to a mole does not cause melanoma. However, repeated trauma can make a mole bleed and inflamed, complicating diagnosis.
Dr. Celina Kazumi Iwasa
VerifiedGMC-Registered · UK Hospital + Private Practice · Skin Cancer Screening Specialist
Dr. Iwasa is a GMC-registered dermatologist working across UK hospital and private practice settings. She specialises in skin cancer screening, mole assessment and dermoscopy, with a focus on UK and European patients across Fitzpatrick I–IV skin types.