Hyperpigmentation is a common, usually harmless condition in which patches of skin become darker in color than the normal surrounding skin.
This darkening occurs when an excess of melanin, the brown pigment that produces normal skin color, form deposits in the skin. Hyperpigmentation can affect the skin color of people of any race.
A common cause of hyperpigmentation is an excess production of melanin. Melanin is a pigment that gives skin its color. It’s produced by skin cells called melanocytes. Several different conditions or factors can alter the production
of melanin in your body.
Certain medications can cause hyperpigmentation. Also, some chemotherapy drugs can cause hyperpigmentation as a side effect.
Pregnancy changes hormone levels and can affect melanin production in some women.
A rare endocrine disease called Addison’s disease can produce hyperpigmentation that’s most obvious in areas of sun exposure, such as the face, neck, and hands, and areas exposure to friction, such as elbows and knees.
The hyperpigmentation is a direct result of an increased level of a hormone in your body that results in increased melanin synthesis.
Excessive sun exposure can also cause an increase in melanin.