“A lot of melanomas are found by patients or their relatives, not by doctors,” says Dr. Mariusz Sapijaszko, president of the Canadian Dermatology Association. 

Do a monthly check using the ABCDE method, and don’t forget hard-to-see places like your back, a frequent site for skin cancer.

Can’t memorize all the red flags? Remember this general rule: If one of your moles looks like an “ugly duckling”—different from the rest—get it checked out.