Hyperpigmentation, better known as dark spots, occurs when the skin produces more melanin, the pigment that gives skin its colour. Most often caused by too much exposure to the sun, hyperpigmentation can also be caused by acne scars and hormone fluctuations. In many individuals, a sunburn from the past or hormone changes in pregnancy can result in brown patches in the upper face, cheeks, and around the mouth. In addition, it is worsened by too much exposure to the sun.