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Health condition

Melanoma warning signs

Melanoma is the most serious form of skin cancer, and recognising its warning signs early, before it spreads, makes it highly curable.

Key points

What matters most, at a glance.

The essentials in plain English - symptoms, when to seek help, who to see and what treatment looks like.

  • Watch for new pigmented lesions or change in an existing mole over weeks to months

  • The ABCDE features and the ugly duckling sign are the core warning signals

  • Melanoma can occur anywhere, including soles, palms, under nails and areas never exposed to sun

  • Specialist: a consultant dermatologist via an urgent two-week-wait referral if melanoma is suspected

Understanding it

About Melanoma warning signs, and what to do next.

Melanoma arises from pigment cells and can develop in a pre-existing mole or as a completely new dark spot; rarer types appear on the palms, soles or under a nail as a new dark streak. The most consistent warning sign is change: in size, shape, colour, elevation or symptoms such as itch or bleeding. Fair skin, sunburn history, many moles and family history all raise risk, but no one is immune.

A suspicious lesion is removed with a small margin under local anaesthetic, and the biopsy result guides any further treatment; thin melanomas caught early have an excellent outlook. Nothing about a worrying mole gets better by waiting, so prompt assessment is always the right call. Most people start with their GP, who can refer to a consultant dermatologist. In many parts of the UK, routine NHS referrals for this kind of problem currently take 20-45+ weeks depending on where you live, whereas an initial appointment with a private consultant is typically available within around two weeks.

A quiet reminder

This guide is for information, not medical advice.

Your GP knows your history and can tell you which parts apply to you. If in doubt, see them.

Frequently asked

Common questions about Melanoma warning signs.

Quick, plain-English answers to what people ask us most.

  • What are the warning signs of melanoma?

    Key warning signs, often remembered through the 'ABCDE' rule, include Asymmetry, irregular Borders, varied Colour, a Diameter larger than about 6mm, and Evolving change in a mole over time. Any mole that's new, changing, itching, bleeding, or simply looks different from your other moles should be assessed.

  • What causes melanoma?

    The main risk factor is significant ultraviolet exposure from sunlight or sunbeds, particularly episodes of sunburn, especially in childhood, alongside genetic factors including fair skin, numerous moles, and a family history of melanoma. Understanding your personal risk factors can help guide how often you should check your skin and seek professional review.

  • Is melanoma dangerous if warning signs are ignored?

    Yes, melanoma can spread to other parts of the body if left undetected and untreated, which is why recognising and promptly acting on warning signs significantly improves the chances of catching it at an early, highly treatable stage. Regular skin self-examination and prompt professional assessment of any concerning changes are key to good outcomes.

  • Is melanoma hereditary?

    There's a significant genetic component, including specific gene mutations identified in some families with multiple affected members, alongside inherited traits like fair skin and numerous moles that increase overall risk. A strong family history of melanoma should prompt more frequent professional skin surveillance.

  • Can melanoma be prevented?

    While you can't eliminate risk entirely, using sun protection consistently, avoiding sunbeds, and avoiding sunburn, particularly in childhood, can significantly reduce your risk. Regular skin self-examination and awareness of the warning signs supports early detection if melanoma does develop.

  • How often should I check my skin for melanoma warning signs?

    Regular self-examination, perhaps monthly, checking all areas of skin including less obvious spots like the scalp, soles of feet and between toes, helps you notice any new or changing lesions promptly. Those with higher risk factors, such as many moles or a family history, may benefit from more frequent professional dermatology checks as well.

  • How is a suspicious mole assessed for melanoma warning signs?

    A dermatologist will examine the lesion, often using dermoscopy (specialist magnified skin surface examination) to assess specific features, and take a biopsy if the lesion shows concerning characteristics. This assessment helps determine whether the mole is likely benign or needs removal for definitive testing.

  • Melanoma warning signs vs a normal, harmless mole — what's the difference?

    Normal moles are typically symmetrical, have smooth, regular borders, uniform colouring, and remain stable in size and appearance over time, whereas melanoma warning signs include asymmetry, irregular borders, varied colour, larger size, and change over time. Knowing what your own moles normally look like helps you notice anything new or different more easily.

  • The 'ugly duckling' sign — what does this mean for spotting melanoma?

    The 'ugly duckling' sign refers to a mole that looks distinctly different from all of a person's other moles, standing out as an outlier, which can be a useful additional warning sign alongside the standard ABCDE criteria. This is because most people's moles tend to share similar characteristics, making a genuinely different-looking one worth having checked.

  • When should I see a doctor about a mole showing melanoma warning signs, and how quickly can I be seen privately?

    Any mole showing one or more warning signs should be assessed by a dermatologist promptly. Private dermatology consultations can typically be arranged within about two weeks, considerably faster than standard NHS routes, though urgent NHS cancer pathways also exist for suspicious lesions.