Melanoma is a cancer which usually starts in the skin, either in a mole or in normal-looking skin. About half of all melanomas start in normal skin.

The number of people who develop melanoma is continuing to rise. More than 8,900 people in the UK are diagnosed with melanoma each year.

Melanoma is more common in women, particularly young women. In the UK it’s the most common cancer in people aged 15–34, but like most cancers it’s more usual for it to happen in older people, as our risk of cancer rises with age. Melanoma is rare in children under 14.

People with black or brown skin are much less likely to get melanoma as their skin is more naturally protected against it.

In women the most common place to develop melanoma is on the legs; in men it’s on the chest or back.

How melanoma develops

Melanoma develops from melanocytes. In melanoma the melanocytes start to grow and divide more quickly than usual and start to spread into the surrounding surface layers of skin. When they grow out of control they usually look like a dark spot or mole on your skin.

Finding and treating melanoma as early as possible is very important. If a melanoma is not removed the cells can grow down deeper into the layers of the skin. These layers contain tiny blood vessels and lymph channels. Lymph channels are tiny tubes which carry lymph fluid and connect to lymph nodes (sometimes called glands) throughout the body. This is part of our immune system, which helps us to fight against infection.

If the melanoma cells go into the blood vessels or lymph channels they can travel to other parts of the body.