Asymmetry: one half of the mole does not match the other half
Border: edges are irregular, ragged, blurred, or notched
Color: multiple colors or uneven color within the mole
Diameter: larger than 6 mm, though smaller moles can still be cancerous
Evolving: changes in size, shape, color, or elevation over time
New symptoms: itching, pain, tenderness, bleeding, or crusting
Ugly duckling sign: looks different from the person’s other moles
Rapid growth: noticeable enlargement over weeks or months
New mole in adulthood: especially if it appears unusual
Dark spot under a nail or on the skin that changes or spreads
Mole that does not heal or keeps scabbing
Mole with a raised area, lump, or thickening
Mole with redness or swelling around it
Mole that looks very different from before
Any mole with concerning changes should be checked by a dermatologist