What is the main cause of hyperpigmentation?

Hyperpigmentation is primarily caused by the overproduction of melanin in the skin. This condition often occurs in response to various stimuli, with sun exposure being one of the most significant triggers. When the skin is exposed to ultraviolet (UV) rays from the sun, it can stimulate melanocytes (the cells responsible for producing melanin) to increase melanin production as a defense mechanism against UV radiation. This heightened melanin output results in darkened patches or spots on the skin, which constitutes hyperpigmentation.

While other factors such as genetics and hormonal changes can play a role in hyperpigmentation, they do not constitute the main cause. For instance, hormonal changes can lead to conditions such as melasma, but the underlying mechanism still revolves around melanin production. Genetic predispositions may also influence skin pigmentation, but they are not direct causes. Therefore, the connection between overproduction of melanin and factors like sun exposure is key to understanding hyperpigmentation.