Sagging skin develops when the skin loses elasticity and the supportive structure beneath begins to weaken. This can affect both the face and body, showing up along the jawline, under the eyes, on the neck, abdomen, upper arms, thighs, or knees. It may appear thin, loose, or crepey, and can be worsened by aging, weight loss, or lifestyle factors. While it’s completely normal, sagging skin can leave you feeling like your outer appearance no longer reflects how you feel inside.