Symptoms of melanoma skin cancer

Some melanomas develop from existing moles. The rest grow on what was previously normal skin. See your doctor if you notice a:

  • new abnormal mole
  • mole that seems to be growing or changing
  • change to a previously normal patch of skin

Checking your skin and moles - ABCDE

It's important to know what your skin looks like normally. This helps you notice any unusual changes.

For parts of your body that are hard to see, you can use a mirror. Or ask your partner or a friend to check those areas.

Doctors use a checklist which explains some of the signs of melanoma to look out for. It's called the ABCDE list. See your doctor straight away if you are worried.

Melanomas can stand out from your other moles. So, if a mole looks very different or is much darker than others you have, you should get it checked. Even if you have none of the ABCDE signs.

A - asymmetrical

This refers to the shape of the mole or abnormal patch of skin. 

Melanomas are likely to have an uneven shape. The two halves may be different shapes or sizes (asymmetrical).  

Normal moles usually have a more even shape and the two halves are similar (symmetrical).

B - border

This refers to the edges of the mole or abnormal patch of skin.

Melanomas are more likely to have irregular edges (border) that are blurry or jagged. 

Normal moles usually have a smooth, regular border.

C - colour

This refers to the colour of the mole or abnormal patch of skin.

Melanomas are often an uneven colour and contain more than one shade. A melanoma might have different shades of black, brown and pink.

Normal moles usually have an even colour. If they have 2 colours in them, the colours are normally symmetrical across the 2 halves.

D - diameter

This refers to how wide the mole or abnormal patch of skin is.

Most melanomas are more than 6mm wide. But they can be smaller if diagnosed early.

Normal moles are usually about the size of the end of a pencil or smaller.

E - evolving

Evolving means changing.

Melanomas might change in size, shape or colour. Or you might notice other changes such as:

  • bleeding
  • itching
  • a change in sensation to a mole or area of abnormal skin
  • a mole becoming crusty

Most melanomas don’t give you symptoms like pain or itching. And some non cancerous (benign) moles or abnormal patches of skin can be itchy. So having some of these changes on their own doesn't mean you definitely have melanoma. But you should still get it checked. 

Melanoma in people with brown or black skin

Melanoma in people with brown or black skin may be more difficult to see. The mole or abnormal patch of skin might:

  • not show any of the ABCD signs
  • be symmetrical
  • be broken and sore (ulcerated)
  • be a pink colour
  • be under a finger or toe nail
  • be on the palm of the hand or sole of the foot 

Pictures of abnormal moles, skin patches and melanomas

Looking at photographs of abnormal moles and melanomas may help you to recognise what is not normal. Remember though, it's what's not normal for you that counts.

Where might you get a melanoma?

You can get a melanoma skin cancer anywhere on the body. But they are more common in certain parts. This differs for men and women.

Melanomas in men are most common on the back, tummy or chest (trunk). In women, the most common site is the legs.

Melanoma of the eye

Rarely, melanoma can start in the eye.

You might be able to see a dark spot if it's growing in the coloured part of the eye (iris).

But if a melanoma is growing inside the eye, there is usually no outward sign. But you might have changes to your eyesight.

This type of melanoma is most often diagnosed during a routine eye check by an optician or eye specialist.

Although melanoma of the eye starts in melanocyte cells, it is a separate type of cancer to melanoma skin cancer. How doctors describe it (the stage of the cancer) and the treatment is different. It is also not linked to exposure to the sun.

Should you see your doctor?

Go and see your GP if:

  • you have any of the ABCDE signs
  • a mole is itching or painful
  • a mole is bleeding or becoming crusty
  • a mole looks inflamed
  • you have an unusual mark or lump on your skin that lasts longer than a few weeks - especially if you are immunocompromised Open a glossary item
  • you have a dark area or line under a nail that is not due to an injury 

The earlier a melanoma is picked up, the easier it is to treat and the more likely treatment is to be successful. So go to your GP as soon as possible.

  • Suspected cancer: recognition and referral
    National Institute of Health and Care Excellence (NICE), 2015 (updated 2023)

  • Scottish referral guidelines for suspected cancer
    Health Improvement Scotland, 2019 (updated 2022)

  • Cutaneous melanoma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up
    O Michielin and others
    Annals of Oncology, 2019. Volume 30, Issue 12, Pages 1884-1901

  • Melanoma in skin of color: Part 1. Epidemiology and clinical presentation
    EK Brungaard and others
    Journal of the American Academy of Dermatology, 2023. Volume 89, Issue 3, Pages 445-456

  • Symptoms: Melanoma skin cancer
    National Health Service (NHS)
    Accessed January 2024

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact with details of the particular issue you are interested in if you need additional references for this information.

Last reviewed: 
01 Feb 2024
Next review due: 
01 Feb 2027

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