Last updated:

Reviewed by:

Dr Bryony Henderson

, Lead GP at Livi

Medically reviewed

Most people have moles and they are usually harmless, but it’s important to keep an eye on any changes in their size, shape and colour.

What are moles?

Moles are coloured, often small spots on your skin, which are caused by melanin. People have moles in many shapes and sizes.

It’s normal for moles to be:

  • Round or oval

  • Smooth edged

  • Flat or raised

  • Smooth or rough

  • Hairy or hairless 

  • Black or brown

  • Anywhere on the body including the face and head

Moles are formed by the build-up of melanocytes, the cells responsible for giving skin its colour. These grow into clusters which form moles. It’s a completely normal response to sunlight but some people will be more prone to having moles than others.

Why should you check your moles?

Moles are completely normal and usually don't cause any problems. But in rare cases, moles can be an early sign of skin cancer.

Melanocytes are the pigment cells that give moles their colour. They're prone to damage that can make them grow uncontrollably, leading to cancerous moles called melanomas. Melanomas are normally found on skin that gets a lot of sun exposure, like the legs and back.

Melanoma skin cancer is the 5th most common cancer in the UK. Around 16,000 new melanomas are found each year. Over 1 in 4 melanomas are found in people under 50.

2,300 people die each year in the UK from melanomas. Checking your moles regularly means you can catch anything unusual early and treat it before it progresses.

When to get a mole checked by a doctor

You should see a doctor if you suspect a mole is showing any warning signs. Remember the signs by thinking of the first 5 letters of the alphabet, from A to E. 

The things to look out for are:

  1. Asymmetry – Healthy skin moles tend to be round. Cancerous moles may grow unevenly or have an irregular border

  2. Border – Normal moles usually have clearly defined, smooth round borders. Melanomas often have blurred or ragged edges

  3. Colour – Moles are normally 1 colour. Melanomas often contain 2 or more shades of brown or black, or sometimes red and pink. Moles that become darker may also be cancerous

  4. Diameter – All moles vary in size, but cancerous moles are usually larger than 6mm (the width of a pencil rubber)

  5. Evolving – Melanomas often change size, shape and colour and may become raised. Cancerous moles can become inflamed or swollen 

Other signs a mole may be cancerous are:

  • Changes like bleeding, itching or crusting to moles

  • ‘Ugly duckling’ moles that look different to other moles on your body

How are cancerous moles treated?

If a doctor suspects a mole is cancerous they’ll refer you to a specialist for further tests. The mole will most likely be removed and sent to a lab to be checked under a microscope for signs of cancer.

Who is at risk of skin cancer moles?

Anybody can develop a cancerous mole. 

Your risk increases if:

  • You have a lot of exposure to UV radiation from the sun or tanning beds, or you frequently burn

  • You have fair skin and blonde or red hair

  • A family member has had skin cancer

  • You have lots of moles

  • You have a weakened immune system

Cancerous moles in darker skin

Darker skin may provide more natural protection against skin cancer than lighter skin, but people with darker skin are still at risk of skin cancer.

Melanomas can be harder to see on darker skin, so sometimes the cancer is more advanced by the time it's found. It's important to regularly check your moles no matter your skin tone. Black or Asian people with cancerous moles often have a type called acral lentiginous melanoma, which is most often found on the palms of the hands, the soles of the feet, or under the nails.

How can I reduce my risk of skin cancer from moles?

UV radiation from the sun is the biggest controllable risk factor for cancerous moles. Preventing sunburn reduces skin damage and lowers the chance of skin cancer.

  • Use sunscreen with a high SPF

  • Avoid direct sunlight from 11 am to 4 pm when the sun is at its strongest

  • Make use of shaded spots

  • Wear protective clothing like a wide-brimmed hat and loose-fitting clothes

  • Avoid sunbeds and sun lamps

Read more on how to stay safe in the sun.

Moles in children

Some babies are born with moles, but they're more likely to appear in childhood and the teenage years. Melanomas are very rare in children and are often slightly different from those in adults. Childhood melanomas are more likely to be red. They can be any size and may be just 1 colour. They may also bleed or feel bumpy.

When should I talk to a doctor about a mole?

See a GP for advice and information if you’re worried about a mole. They can assess your mole for any signs of melanoma that may need a closer look.

Last updated:
Reviewed by:
Dr Bryony Henderson, Lead GP at Livi