When to worry about a mole: changes to check and when to see a doctor

Most people have moles, and most are harmless. Checking your skin from time to time is still sensible, because melanoma, a type of skin cancer, can start in or look like a mole. The NHS stresses that any change to a new or existing mole is worth getting checked. This post explains what a typical mole looks like, the changes to watch for and what happens when you see a doctor.

The short answer

• A new mole, or a change in an existing mole, may be a sign of melanoma.
• The NHS describes changes to look for: uneven shape or edges, a mix of colours, a large size (often more than 6mm), and a mole that changes over time.
• Other signs include a mole that is swollen, sore, bleeding, itchy or crusty.
• See a doctor about any mole that changes size, shape or colour, or any new or unusual mark that does not go away after a few weeks.

What the NHS says to look for

The NHS says normal moles are usually round with smooth edges, one colour, and small, often about the size of the end of a pencil or smaller. They do not usually change over time. Melanomas differ in these ways:

• Shape. Melanomas are often an uneven shape, may have two different halves and have uneven edges.
• Colour. They are often a mix of two or more colours.
• Size. They tend to be bigger, often more than 6mm wide, but can be smaller if found early.
• Change. A mole that changes size, shape or colour may be a melanoma.

Other signs are moles that are swollen and sore, bleeding, itchy or crusty. Melanomas can appear anywhere, and they are more common in areas often exposed to the sun. The NHS adds that rarer types can affect the eyes, soles of the feet, palms of the hands or genitals, and a dark area under a nail that is not caused by an injury should also be checked.

Because melanoma can also appear on the palms, soles and under the nails, look in those places too. A partner or friend can help check areas you cannot see, and a mirror helps.

How to check your skin

1. Choose a well-lit room and use a full-length mirror and a hand mirror.
2. Look at your whole body, including the scalp, between the toes, soles, palms, behind the ears and under nails.
3. Note the position, size and look of moles. Taking dated photos on your phone lets you compare later. Store them privately and keep them to yourself.
4. Repeat every so often, so changes stand out.

The aim is to spot change, not to diagnose. A mole that looks unusual to you deserves attention even if you cannot say why.

When to see a doctor

The NHS advises seeing a GP if:

• you have a mole that has changed size, shape or colour
• you have a mole that is painful or itchy
• you have a mole that is inflamed, bleeding or crusty
• you have a new or unusual mark on your skin that has not gone away after a few weeks, including on the palms or soles
• you have a dark area under a nail that is not caused by an injury

The NHS says finding a melanoma as early as possible can mean it is easier to treat. Do not wait for several months to see whether a changing mole settles.

What happens at the appointment

The NHS says you will be asked questions about your health, family history, medical conditions and symptoms. The doctor looks at the mole and the rest of your skin. If they are concerned, they may refer you to a skin specialist (dermatologist) who may take a sample or remove the mole to be examined. You are not expected to decide anything alone: ask what each step is for and when you will hear the result.

Our guide to a dermatology consultation describes a typical visit, the skin cancer screening service page gives an overview, and the dermatology topic has more background. For HealthNaro, listed clinics are not recommendations, so check a clinician's registration before you book.

Reducing risk from the sun

The NHS says sunburn increases the risk of skin cancer and that there is no safe or healthy way to get a tan. Our post on how to use sunscreen covers the practical steps. People with many moles, a history of sunburn, a family history of skin cancer, or a past skin cancer may be advised to have regular skin checks, so ask a doctor what is right for you.

Frequently asked questions

Are all changing moles cancer?

No. Moles can change for harmless reasons. The NHS still advises having any change checked, because that is how melanoma is found early.

Can a mole be removed for cosmetic reasons?

Many places offer removal, but costs and rules vary and a mole that has been removed should be examined in a laboratory. Ask a doctor first.

Do moles appear in adulthood?

New moles can appear. The NHS lists a new mole as a possible sign of melanoma, so have any new mole that looks unusual checked.

Can I use a phone app to check a mole?

Apps cannot replace an examination. Use photos to track changes and show a doctor.

General information only

This article is general information, not medical advice. It does not diagnose skin conditions. If you notice a mole that bleeds, changes quickly or looks unusual, see a doctor promptly. You can send an inquiry to ask HealthNaro for help finding a clinic.