Moles

Moles are small dark marks on the skin. They are a collection of skin pigment cells called melanocytes.

Moles are usually brownish, although some may be darker or skin-coloured. They can be flat or raised, smooth or rough, and some have hair growing from them. Moles are usually circular or oval in shape, with a smooth edge.

They can start to look different over time and sometimes respond to hormonal changes, such as during pregnancy, adolescence and the menopause. Some moles even disappear over time or fall off, often without you realising.

When do moles develop?

Some moles are present at birth. These are called congenital melanocytic naevi. However, most moles develop during the first 20 years of life (and sometimes into the 30s and 40s).

Halo naevi are moles that are sometimes seen in children and young adults. They are surrounded by a white ring, where the skin has lost its colour. The skin regains its colour when the mole in the centre of the halo disappears, which can take a few years.

In this section

Seborrhoeic keratoses are skin blemishes that can mimic moles. They are benign (not cancerous) and are common in older people. They can be skin-coloured, brown or black, and look like raised warts.

In general, moles often develop if you spend a lot of time in the sun, and tend to appear on parts of the body that catch the most sunlight, such as your face.

Malignant melanoma

Most moles are normal and harmless, but in a few cases they can develop into malignant melanoma, an aggressive form of skin cancer.

Malignant melanoma is the most serious type of skin cancer and is usually caused by short periods of strong sunlight, such as on a two-week holiday.

Malignant melanoma can appear anywhere on the body. It may be a dark, fast-growing spot where there was not one before, or a mole you already have that changes size, shape or colour, and bleeds, itches or reddens.

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