You're at an increased risk of melanoma if you have lots of moles on your body, particularly if they're large (over 5mm) or unusually shaped.
For this reason, it's important to monitor your moles for changes and avoid exposing them to intense sun.
Read more about checking your skin.
Other risk factors
You're also more likely to develop melanoma skin cancer if you have:
- a close relative who's had melanoma skin cancer
- pale skin that doesn't tan easily
- red or blonde hair
- blue eyes
- a large number of freckles
- previously damaged your skin through sunburn or radiotherapy treatment
- a condition that suppresses your immune system, such as HIV, or you take medicines that suppress your immune system (immunosuppressants)
- a previous diagnosis of skin cancer
The risk of developing skin cancer also increases with age.
Cancer Research UK has more information about melanoma risks and causes.