How do I know if a mole is dangerous

Look for the ABCDEs of melanoma. A is for Asymmetry, meaning one half doesn't match the other. B is for Border, meaning the edges are irregular, ragged, or blurred. C is for Color, meaning the mole has uneven shading or multiple colors like brown, black, red, white, or blue. D is for Diameter, meaning it's larger than 6mm, about the size of a pencil eraser. E is for Evolving, meaning it's changing in size, shape, color, or starts bleeding or itching. Any mole that bleeds, itches, oozes, or appears suddenly and grows quickly should be evaluated promptly. See a dermatologist if you notice any of these warning signs, or if you have a mole that simply looks different from your others.