Sagging skin occurs when the skin loses elasticity and firmness, often due to aging, collagen depletion, sun damage, or lifestyle factors. It commonly affects areas like the cheeks, jawline, neck, and under the eyes. Signs include loose or drooping skin, fine lines, and a less defined facial contour. Sagging skin can make the face appear tired or aged, and may benefit from treatments that stimulate collagen and restore structural support.