An uneven skin tone, or hyperpigmentation, is the result of an over production of melanin. Melanin is what gives skin and hair its color, helps protect skin against damaging UV light and absorbs heat from the sun. However, an overproduction of melanin stimulated by excessive sun exposure, hormones, or scarring, leads to a mottled, uneven skin tone.
1) Sun exposure: When skin is repeatedly exposed to UV light, sun damage occurs. Brown spots appear as a result of too much melanin being produced to help protect skin from UV light.
2) Hormones: Melasma is hormone-related hyperpigmentation caused by increased hormone stimulation. It is most commonly experienced by women who are pregnant (which is why it’s also known as the “mask of pregnancy”) or taking contraceptives, but can also be a reaction to cosmetics or medications.
3) Post-Inflammatory Hyperpigmentation: This is a darkening of skin that’s the result of scarring, which can be caused by acne lesions or skin injury.