Most moles signify nothing more than a harmless cluster of cells on your skin. Irregular moles, however, can be a warning sign that you are developing skin cancer. The more prone you are to developing moles, particularly if you're fair-skinned, the higher your risk for skin cancer. Learn to identify irregular moles, and always have any suspicious spots on your body checked out by a medical professional.
Identification
A mole is a growth on any part of your body caused by a cluster of melanocytes, the cells that give your skin its color and cause it to tan when exposed to sunlight. They might be flat or raised off the skin. They can be pink, brown or flesh-colored, and some have hair growing out of them. Most moles are round and the size of a pencil eraser or smaller, according to the U.S. National Cancer Institute, though they can be larger than an inch in diameter.
Prevalence
Most people have at least 10 moles somewhere on their body, according to the NCI. It's somewhat rare for babies to be born with moles--only about 1 in 100 births, according to the American Osteopathic College of Dermatology (AOCD)--but you develop most of your moles sometime through adolescence and early adulthood. Rarely, you can still develop moles after 40. Moles can grow, become raised or even disappear throughout your lifetime.
Considerations
Moles often occur as the result of sun damage, according to the AOCD. If you have a lot of them, such as more than 10 or 20, you have a moderately higher risk of developing skin cancer. Moles themselves are not skin cancer, but the most aggressive and dangerous form of skin cancer, melanoma, often begins within moles. Dermatologists can remove suspicious moles and determine whether they are developing into skin cancer.
Warning
Dermatologists often refer to the ABCD method of determining whether a mole is a skin cancer concern. "A" stands for asymmetry, meaning the mole does not have a uniform appearance. "B" refers to the border, as any mole that does not have a round border is a concern. "C" is short for color. Most moles are the same color throughout, but moles that contain several different colors or that are extremely dark should be examined. "D" stands for diameter, as you should check out any mole larger than the eraser on the tip of a pencil. Some dermatologists add an "E," for evolving, meaning you should watch moles for any sudden changes in appearance. About one in 10 people have an irregular mole, according to the AOCD, and you should have a dermatologist examine any such mole.
Prevention
If you have several moles on your skin, you should monitor them closely and visit a dermatologist once a year for a thorough skin examination. Avoid the sun whenever possible, and use sunblock when you have to be exposed to the sun. While regular moles pose no danger to you, a dermatologist can remove them if you think they're unsightly or if they're in a spot where your clothing chafes and irritates them. Removing a mole leaves a small scar, however, so consider that effect before you have it removed.
