A for Asymmetry: One half of the mole or birthmark does not match the other half. B for Border: Edges are irregular, ragged, notched, or blurred. C for Color: The color is not uniform and may include shades of brown, black, or other colors. D for Diameter: The spot is larger than 6 millimeters across (about the size of a pencil eraser), although melanomas can sometimes be smaller. E for Evolving: The mole is changing in size, shape, or color.
Other warning signs include sores that do not heal, new growths, redness or swelling beyond the border of a mole, and changes in sensation, such as itchiness, tenderness, or pain.
