What is the reason why the skin turns black with the weather?

There are many reasons for skin blackening. First, favorite foods are rich in zinc, copper and iron. Some foods are also the bane of skin blackening. Second, drugs are compatible with melanin. Many drugs also need to change the normal skin color. Third, some diseases are the inducement. Many diseases will change the normal skin color and make it black. Fourth, the harm of the natural environment to the skin. The culprit is ultraviolet rays, which stimulate melanin in the skin and induce skin lesions such as freckles. Even in the dark, "ultraviolet" is still very strong.

Women also secrete a lot of hormones during pregnancy, such as estrogen and progesterone. Some of these hormones can make breasts feel pain, and also make breasts bigger and areola bigger. So these are all regulated by normal hormones in the body.