why do people have dark spots
Dark spots are the result of the overproduction of melanin (skin pigment). It's not fully understood why dark spots develop, but aging and UV light exposureâeven exposure to artificial UV light, like the kind used in tanning bedsâare major causes. Dark spots can develop anywhere, but they are most likely to appear on the parts of the body that receive the most sun exposure, including: 1  The face. 2  The backs of the hands. 3  The shoulders. 4  The arms. 5  The back.