A new mole or spot appears on your skin
A mole changes in size, shape, or color
A mole has uneven or irregular borders
A mole has multiple colors or an unusual color
A mole is larger than about 6 mm, though melanoma can be smaller
A spot looks different from your other moles
A mole itches, hurts, bleeds, or crusts
A mole or spot does not heal
A mole becomes raised or develops a lump
A mole changes quickly over weeks or months
A dark streak appears under a nail
A sore on the skin keeps coming back
You notice a spreading pigmented patch on the skin
You have a changing lesion on the face, back, legs, or other sun-exposed area
You have a family history of melanoma
You have many moles or atypical moles
You have had significant sun exposure or sunburns
You should get a dermatologist to examine any suspicious or changing spot