(1) Ultraviolet radiation is the number one killer of spots. Generally, the melanin deposits caused by sun exposure are eliminated with the body's metabolism, but some people may have a slower metabolism or older age, leaving melanin and forming dark spots. .
(2) Metal substance poisoning caused by the use of expired or inferior cosmetics, such as lead, mercury, and arsenic poisoning.
(3) During skin trauma, foreign bodies such as dust and ink embedded in the wound; use of iodine, purple syrup; or over-eating of foods containing pigments, such as soy sauce, black fungus, etc., will cause pigmentation and form dark spots.
(4) Living habits issues. Bad lifestyle habits such as stress, partial eclipse, lack of sleep can also increase melanin. Therefore, people with unstable sleep time have poor skin metabolism, which will affect the production of melanin particles.