Melanoma is the most serious type of skin cancer and it develops in the cells of your skin that produce pigment called melanin. Melanoma is a cancer that starts on your skin and may spread internally to other parts of your body if not treated. Look out for moles that change shape, size or colour. Contact your doctor right away if you notice any changes in your moles or an unusual freckle or spot. One important way of preventing melanoma is by avoiding extended exposure to UV light that causes sunburn, and by wearing a protective sunscreen when you go outside. Melanoma tends to run in families so if you have a close relative that has melanoma, you should get regular skin checks from a doctor.