Researchers from King’s College London found that having more than 11 moles on your arm is an indicator of an increased risk of developing skin cancer.
3,600 twins had a skin exam that recorded their skin type, hair and eye color, and freckles, as well as mole counts on 17 different areas of the body.
Those who had 11 moles on their right arm were more likely to have 100+ moles on their body. Most adults have between 10 and 40 moles on their body, according to the American Academy of Dermatology.
“Counting all of your moles can be difficult and time-consuming. This is an easy way to tell if you’re at risk,” Marie Leger, MD, PhD, an assistant professor of dermatology at NYU, tells Yahoo Health.
“Moles on the right arm can be tied to a person’s melanoma risk because this indicates that the body has been exposed to the sun,” she explains.
Scientists discovered that areas above the elbow are a good predictor of a person’s skin cancer risk.
“If the moles are located on the upper arm, this indicates that the arms themselves have been exposed to the sun and potentially without regard to wearing protective clothing, sunscreen, or taking other precautionary measures,” she says. “The fact that the arms themselves have an excess number of moles suggests extreme amounts of sunlight and abuse to the skin.”
How can you tell the difference between a mole and a freckle?
Freckles are pictured, left. The two darker spots in the photo on the right are moles.