There are several clues and common occurrences that could point to things such as the melanocytes creating too much melanin in the skin, for this reason people of darker skin are more prone to melasma and it's strange pigmentation. Other possible causes for melasma might be sun exposure. Exposure to too much sunlight makes your skin create more melanin making your skin darker, thus this could be a cause for melasma and for worsening its effect on people. Hormones and cosmetics might also be the reason why melasma occurs more commonly in women than anyone else.
Melasma comes with very obvious signs that indicate that a person indeed has the disease. The common signs of melasma are dark-brown patches appearing on the face. The patches mostly occur around the area of the face like the cheeks, forehead, chin, and sometimes around the neck although it’s less common. Thankfully, melasma is not considered a dangerous disease nor is it contagious in any way, However, as with any skin disease that can change one's appearance, most people dislike their appearance and seek treatment in whatever way