Moles are usually harmless, but there are certain signs that could point to a serious problem like melanoma, which is a dangerous type of skin cancer.
Melanoma can be deadly if it is not caught early. One of the warning signs to look for is when moles have irregular or uneven borders. Instead of being smooth and round, the edges may be jagged or not well-defined. Another sign is if the color of the mole stars to change.