Which of the following is a common cause of hyperpigmentation?

Sun exposure is a common cause of hyperpigmentation due to the way ultraviolet (UV) rays impact the skin. When the skin is exposed to sunlight, it reacts by producing more melanin, the pigment responsible for skin color, as a protective mechanism against UV damage. This increased melanin production can lead to dark spots or patches on the skin, often referred to as sunspots or lentigines. Over time, this cumulative sun exposure can significantly contribute to uneven skin tone and hyperpigmentation, making it a well-recognized factor in the development of this skin condition.

Although hormonal changes, genetic factors, and age-related decline can also influence skin pigmentation, sun exposure remains the most prevalent and preventable cause of hyperpigmentation. This understanding emphasizes the importance of sun protection as a key strategy in skincare to avoid hyperpigmentation and maintain a more even complexion.