During a skin check, you should look for new growths, sores that wonât heal, or changes in existing moles. Pay particular attention to the ABCDEs of melanoma: - Asymmetry: One half of the mole doesnât match the other. - Border: The edges are irregular or blurred. - Color: The color is not uniform and may include shades of brown, black, and sometimes patches of pink, red, white, or blue. - Diameter: The spot is larger than 6 millimeters across (about the size of a pencil eraser). - Evolving: The mole is changing in size, shape, or color.