Skin cancer: how to check your moles, spots or lesions

Every day in the UK, two people in the 15 to 35 age group are diagnosed with malignant melanoma.

The British Skin Foundation's Hermione Lawson explains that we all need to be vigilant: a mole that grows, changes shape or looks unusual may be a sign of skin cancer. A common way to assess our moles is to use the ABCDE guideline:

A - Asymmetry - look for any asymmetry in the mole.

B - Border - normal healthy moles tend to be round with smooth clearly defined borders, concerning moles may have ragged or blurred borders.

C - Colour - moles that are uneven in colour or their colour is changing needs checking.

D - Diameter - any mole that is growing in size in combination with other changes.

E - Enlargement - elevation or enlargement of the mole is a sign that it is evolving and therefore needs checking.

How often should I check my skin for any changes to moles?

The best way to detect skin cancer is to check your skin regularly, about once a month. You should examine the skin all over your body, from top to toe. Ask a friend or member of your family to look at areas you can't see such as your scalp, ears and back.

What is the most important thing to look out for?

Look out for moles or patches of skin that are growing, changing shape, developing new colours, inflamed, bleeding, crusting, red around the edges, particularly itchy, or behaving unusually. If you have any spots that aren't healing, these too need reviewing. A good rule of thumb is remember to use your ABCDE rule as a reminder. 

What should I do if I notice something unusual?

If in doubt, get it checked by your GP straight away. If he or she is concerned, they will refer you to see a consultant dermatologist - an expert in diagnosing skin cancer.

How likely is it to be malignant melanoma?

Malignant melanoma is the least common but more serious form of skin cancer, which can be fatal if not caught and removed early. It is disproportionately high amongst young people, and people most at risk include those with pale skin who burn easily, those who have suffered past episodes of sunburn, people with many ordinary or unusual moles and those with a family history of melanoma.

What causes melanoma?

Melanoma is caused by an abnormal development of skin cells that is thought primarily to be caused by UV light exposure from the sun. The sudden intense exposure (i.e. whilst on holiday or during a heat wave) to the sun, if not careful, may cause sunburn.  Therefore, it is vitally important we protect our skin health with regular application of a high factor sun protection – even when we are in the shade or the day is cloudy.

Cancer Research UK states, there is no such thing as a safe tan, people have an increased risk of melanoma if they have ever used a sunbed. This is backed up by research from The International Agency into Cancer (IARC) who have classified using sunbeds as a cause of melanoma

Should I be worried about bothering my doctor?

It’s a pleasurable experience to be able to tell a patient they have nothing to worry about, so people should always get a professional opinion at the first sight of any change.

Is it worth paying to have my moles mapped or screened privately?

Not all screening services operate to the same standard. There is a real danger that not only will these unevaluated commercial “mole screening” devices over-diagnose, but that they may also under-diagnose and falsely reassure the customer, who then does not seek a referral for a changing mole.

Therefore, self-monitoring and early diagnosis by an experienced doctor would remain our advice to anyone worried about the development of skin cancer.

Self-monitoring can be easily achieved through keeping an evolution diary. If you have a particular mole/lesion you are concerned about place a pencil at the side of it and take a photograph. A month later, repeat this process and assess each photo for any evolution. Through keeping an evolution diary in this manner gives tangible evidence for both your clinician and yourself on any changes to any moles/lesions have made.

Further information about skin cancer

The British Skin Foundation has a useful "skinformation section" with plenty of facts about skin cancer and sun safety, as well as an A-Z of skin diseases.

Members of Benenden are able to use the 24/7 GP advice line, allowing them to speak to a doctor about any health concerns they may have.

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Medically reviewed by Llinos Connolly in January 2024.