Genetics, sun exposure, and some drugs are the three main factors that contribute to skin pigmentation.
[4] Hyperpigmentation results from an increase in melanin synthesis, which is mostly brought on by sun exposure, dermatological disorders, hormones, aging, genetic factors, skin injuries or inflammation, and acne.
Sun exposure, which greatly increases the synthesis of melanin, is the most common cause of hyperpigmentation.
Melanosomes, which are organelles containing melanin, must be transported and increased during hyperpigmentation and tanning, while they shrink during hypopigmentation.
Skin pigmentation may also become more intense when certain drugs, such birth control pills, are taken concurrently.