Melanoma, also called malignant melanoma, is a type of skin cancer. It's often caused by too much sun exposure.
The first sign of melanoma is often a new mole or a change in the appearance of an existing mole.
Melanoma can usually be treated with surgery if it's caught early. If it has spread, treatment may involve other treatments, like radiotherapy.
You cannot always prevent melanoma, but you can reduce your chances of getting it by taking care not to get sunburned.