Under-eye bags can stem from fat, fluid, loose skin, or a combination of all three, and each causes different looks, behaves differently, and responds to different treatments. Orbital fat displacement creates persistent fullness that doesn’t change with sleep or lifestyle, and requires surgical repositioning through lower blepharoplasty. Fluid-related puffiness fluctuates throughout the day and responds to lifestyle adjustments or medical management rather than surgery. Skin laxity creates a soft, creased appearance that resurfacing treatments or surgery can address, depending on severity. Identifying the correct cause before choosing a treatment matters enormously; adding filler where fat should be removed makes the problem worse, not better. Many patients have a combination of all three factors, so the treatment plan needs to address each appropriately. A consultation with a double board-certified plastic surgeon is the clearest path to understanding what is actually happening and choosing the right solution.

source: https://liftplastics.com/whats-really-causing-your-under-eye-bags/