Asymmetry means one half of a mole does not match the other half. Normal moles are symmetrical. When checking your moles or freckles, draw an imaginary line through the middle and compare the two halves. If they do not look the same on both sides, have it checked by a dermatologist.
If the border or edges of the mole are ragged, blurred, or irregular, have it checked by a dermatologist. Melanoma lesions often have uneven borders.
A mole that does not have the same color throughout or that has shades of tan, brown, black, blue, white, or red is suspicious. Normal moles are usually a single shade of color. A mole of many shades or that has lightened or darkened should be checked by a doctor.
A mole is suspicious if the diameter is larger than the eraser of a pencil.
A mole that is evolving – shrinking, growing larger, changing color, begins to itch or bleed – should be checked.