Changes in appearance or size of either breast (including thickening or fullness that feels different from the rest of the breast)
A hard lump or knot near your underarm
A change in the nipple (it could become suddenly pushed in, or inverted)
Dimples, puckers, bulges, or ridges on the skin of the breast
Nipple discharge or blood
Itching, scales, sores, or rashes. Different skin tones can present rashes differently.
“Redness” accompanied by warmth, swelling, or pain.