Moles are extremely common. By the time you reach adulthood, it's quite normal for between 10 and 40 of these small, coloured spots to have developed on your skin. Most are harmless, but it's important to check them regularly, as occasionally they can become malignant (cancerous).
So what causes moles?
Moles form when specialised skin cells (called melanocytes) grow in a cluster instead of being spread throughout the skin. The melanin, or pigment, produced by these cells means they are usually darker than the rest of the skin.
Moles can develop anywhere on the body. They come in all shapes and sizes and can appear bumpy, smooth, flat, raised or hairy. They tend to be more prominent in fair-skinned people, and sometimes run in families.
It's common for babies, children and teenagers to have moles too. In fact, it's quite usual for new ones to appear during childhood. They can also fade or disappear with age.
Know what's normal for you
While most moles are nothing to worry about, occasionally they can develop into something more serious, so it's important to inspect them frequently and keep an eye on any new ones that appear.
If you notice any change in a new or an existing mole, get it checked out. The following can be signs of melanoma, a type of skin cancer which develops from the melanocytes in the skin:
• Changes in size or shape
• A ragged outline
• Uneven colour
• Itching, crusting, flaking or bleeding
• Getting larger or more raised from the skin
Use a mirror to help you inspect moles in places you can't easily see, or ask a partner or friend to help. Pay special attention to areas of the body that are often exposed to the sun. The most common location for melanoma in men is the back, and in women it's the lower leg.
What to do if you're worried
Always get any moles you’re worried about checked out by your doctor as soon as possible. Specialist, paid-for mole scanning and mapping services are also available at some pharmacies. These can pick up any changes or irregularities that might need further investigation.
Stay safe in the sun
Overexposure to UV rays can lead to a change in the structure of a mole and increase the chance of it becoming a cancerous one. This means that you should always protect your skin by taking the following measure:
• Stay in the shade between 11am-3pm, when the sun is at its strongest
• Cover up with loose-fitting clothing and wear a hat and sunglasses
• Apply sunscreen to exposed skin even when the weather is cloudy
• Do not use sunbeds
Next steps
The three key things to remember about moles are:
• Always protect your skin from the sun, even when the weather is cloudy
• Check any existing moles regularly, and check for new ones too
• Go to the doctor if you find a mole that's changed in any way or if you have any concerns