Moles are common clusters of pigmented skin cells and are usually harmless when they remain stable in size, shape, and color. Most people have them, and the vast majority never cause problems. However, changes in a mole—or the appearance of new, unusual skin spots—can sometimes signal melanoma, a serious but treatable form of skin cancer when caught early.

Dermatologists often rely on the ABCDE guide to assess whether a mole needs medical attention:

• Asymmetry: one half doesn’t match the other

• Border: edges are irregular, blurred, or uneven

• Color: varied or unusual shades within the same spot

• Diameter: larger than about 6 millimeters (roughly a pencil eraser)

• Evolving: any change over time in size, shape, color, or sensation

A mole that meets one or more of these criteria doesn’t automatically mean cancer, but it does warrant evaluation by a healthcare professional.

Not all concerning skin changes involve moles. Some growths linked to sun exposure, such as rough or scaly patches, can develop into skin cancer if left untreated. Other types of skin cancer may appear as pearly bumps, firm red nodules, or sores that crust, bleed, or fail to heal. There are also benign growths that can resemble cancer, which is why professional assessment is important rather than self-diagnosis.

Signs worth checking include a spot that appears suddenly, grows quickly, bleeds without clear cause, causes persistent pain or itching, or changes in color or texture. Regular self-checks—about once a month—help you notice changes early, and routine dermatologist visits add another layer of protection, especially for people with significant sun exposure or a family history of skin cancer.

Prevention plays a key role. Using sunscreen, avoiding tanning beds, wearing protective clothing, and being mindful of sun exposure all reduce risk. Most skin changes turn out to be harmless, but paying attention and acting early when something looks different helps ensure the best outcomes.

Caring for your skin is not about fear—it’s about familiarity. Knowing what’s normal for you makes it easier to notice when something deserves a closer look.