Use the ABCDE check: Asymmetry, irregular Border, varied Color, Diameter over 6mm, and Evolving - any change in size, shape, color, or new bleeding or itching - plus the ugly-duckling rule: a mole that looks different from all your others.
Most moles are harmless and plenty of moles are normal; the check exists to catch the changing outlier. Anything flagged deserves a prompt skin check - a biopsy takes minutes, and melanoma caught early is highly treatable while waited-on melanoma is not. Do a monthly head-to-toe check, including scalp, soles, and between toes. Pymander is a free AI doctor, 24/7 by text, and can help you think through a change.
What to do
Common questions
How do you tell if a mole is cancerous?
Dermatologists use ABCDE. A is Asymmetry - one half does not match the other. B is Border - ragged, notched, or blurred edges instead of smooth ones. C is Color - multiple shades of brown, black, or patches of pink, red, white, or blue in one mole. D is Diameter - bigger than about 6mm, a pencil eraser, though melanomas can be smaller. E is Evolving - any change in size, shape, color, or height, or new bleeding, itching, or crusting. Add the ugly-duckling rule: a mole that simply looks different from all your others deserves attention, even if it passes A through D. Most moles are harmless, and having lots of moles is normal - the point of the check is catching the one changing outlier. If anything flags, book a skin check promptly; a dermatologist can biopsy a suspicious mole in minutes, and melanoma caught early is highly treatable, while waited-on melanoma is not. Check your skin head to toe monthly, including scalp, soles, and between toes. Pymander is a free AI doctor, 24/7 by text, that can help you think through whether a change warrants a visit.