Any new 'mark' on the skin must be checked by your GP to rule out skin cancer. Although women are more likely to develop skin cancer, men are more likely to die from it, probably because they don’t go to the doctor soon enough!
Any mole on your skin which changes shape, colour, size, itches or bleeds must be examined as these are signs of possible malignant melanoma, the most dangerous form of skin cancer.
Keep an eye on moles if you're fair skinned with blue/grey/green eyes and sunburn easily as you have a higher risk than most of developing skin cancer. Any mole larger than the blunt end of a pencil should be watched.