Hyperpigmentation of the skin is caused by an increase in melanin, a substance in the body that is responsible for color (pigment). The skin develops brown spots in areas that have been exposed to the sun. Pregnancy and the intake of birth control pills can also cause this condition to develop and sun exposure can worsen it. People with darker Asian, Mediterranean or African skin tones are more prone to hyperpigmentation. Topical treatments containing kojic acid, hydroquinone, retinoids or glycolic acid help in lightening the skin. Other treatments include lasers, chemical peels and microdermabrasion.