Factors that cause hyperpigmentation depend on the type of discoloration.
Melasma is sometimes referred to as the “mask of pregnancy” since it’s often a side effect of hormonal changes during pregnancy. Other factors like sun exposure and certain skincare products may cause melasma.
For sun damage, excess sun exposure causes your skin cells to produce more melanin, darkening the skin in certain areas as a way to protect itself. When that excess pigment doesn’t fade away, it creates sun spots/age spots.
Acne or other skin trauma can cause post-inflammatory hyperpigmentation. Darker skin tones can be more susceptible to this type of hyperpigmentation, as this skin type can take longer to heal and lighten dark spots.