Detailed answer

Dark spots, also known as hyperpigmentation, generally develop gradually over time and are the result of various factors such as sun exposure, hormonal changes, inflammation, or skin injuries. While some individuals may notice the appearance of dark spots seemingly overnight, they are likely the result of previously unnoticed changes in the skin or an increased visibility due to contrast with surrounding skin. It is essential to protect your skin from sun exposure, use targeted skincare products, and consult a skincare professional for an accurate diagnosis and appropriate treatment options for dark spots.