Quick read
Key points
- 1
Melanoma is a serious form of skin cancer that develops in the cells that produce skin pigment (melanocytes). It can develop from an existing mole or appear as a new spot on the skin, and is strongly linked to sun exposure and sunburn, particularly earlier in life.
- 2
Topic-specific prevention and risk reduction will be added during the article-specific evidence audit.
- 3
A mole changes in size, shape, colour, or texture
01 · Know
What is Skin cancer (melanoma)?
Melanoma is a serious form of skin cancer that develops in the cells that produce skin pigment (melanocytes). It can develop from an existing mole or appear as a new spot on the skin, and is strongly linked to sun exposure and sunburn, particularly earlier in life.
Early detection greatly improves treatment success, which is why knowing your skin and checking moles regularly for change is so important. The ABCDE rule — Asymmetry, Border, Colour, Diameter, and Evolution — is a useful guide for spotting concerning changes.
02 · Understand
Clinical context
Self-care advice
See your GP promptly for any new or changing mole — most are harmless, but early assessment is essential to rule out melanoma.
03 · Act
When to see a doctor
- 1A mole changes in size, shape, colour, or texture
- 2A mole has an irregular or blurred border, or uneven colouring
- 3A new mole or dark spot appears, especially after the age of 40
- 4A mole becomes itchy, painful, or starts to bleed or ooze
- 5You notice a dark streak under a nail or a new pigmented area anywhere on the skin
04 · Prevent & manage
Practical steps
Take these self-care steps
These measures can help ease symptoms, support recovery, and reduce the chance of things worsening — but they don't replace medical advice if symptoms are severe or persistent.
- 1Check your skin regularly.Get to know your own moles and skin, and check for any new or changing spots every few months.
- 2Use the ABCDE rule.Watch for Asymmetry, an irregular Border, multiple Colours, a Diameter over 6mm, and any Evolution (change) in a mole.
- 3Protect your skin from the sun.Use a high-SPF sunscreen, seek shade, and cover up during peak sun hours to reduce future risk.
- 4Avoid sunbeds.These significantly increase melanoma risk and offer no health benefit.
- 5Get any concerning mole checked promptly.Don't wait to see if a changing mole settles down — early assessment gives the best outcome.
Evidence
References
BarnMD Health Intelligence uses authoritative and clinically relevant sources appropriate to the topic. References are shown so readers can inspect the evidence directly.
- HSE: Skin cancer (melanoma) ↗
Medical information notice
Health education, not individual medical advice
BarnMD Health Library provides general health education for public health literacy. Reading this article does not establish a doctor-patient relationship and this information is not a diagnosis, prescription, or personalised treatment plan. If you have symptoms or concerns about your health, seek appropriate advice from a qualified healthcare professional. If you develop emergency warning signs, seek urgent or emergency medical attention.
BarnMD Bottom Line
Melanoma is very treatable when caught early, which is why regular skin checks and prompt assessment of any changing mole are so important.
A mole that's changing — in size, shape, colour, or sensation — is the single most important thing to get checked promptly.