What to look for

Skin lesions are abnormalities that occur on or under the surface of the skin. They are normally associated with ageing, but can appear at any stage of your life. Skin lesions are common and usually harmless, but occasionally they can be warning signs of something more serious, including skin cancer.

Fortunately, cancerous lesions can be identified with vigilance, allowing the cancer to be treated more effectively. Click on the basal cell carcinoma, squamous cell carcinoma, actinic keratosis and melanoma pages to learn more about the different types of skin lesion to monitor for.

Broadly speaking, you should monitor your skin for spots that:

  • Change colour, size or shape
  • Appear different to the rest
  • Are asymmetrical or have uneven borders
  • Are wider than 6mm
  • Feel rough or scaly (sometimes you can feel a lesion before it becomes 
  • visible)
  • Are multi-coloured
  • Are itchy
  • Are bleeding or oozing
  • Look pearly
  • Look like a wound but do not heal

Don’t assume that a suspicious spot is harmless just because it is painless. Not all cancerous lesions are painful.


The ABCDE rule

An easy way to remember some of these signs is the ABCDE rule.

  • Is the lesion Asymmetric?
  • Does it have indistinct or uneven Borders? 
  • Does it change Colour?
  • Is it larger than 6mm in Diameter?
  • Has its size, shape or behaviour Evolved over time?

The ‘Ugly Duckling’ sign

All your moles should look fairly similar; the same shape and colours. If a new lesion appears that is different from the rest, it may be suspicious. This is called the ‘Ugly Duckling’ sign.