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See your health care provider for consultation. As the skin and muscles under the eyes weaken with age they start to sag and to allow fluid or fat to build up behind them, creating bags. However, many other factors can cause under-eye bags. Temporary ones, for example, could stem from lack of sleep; an allergic reaction to a drug, cosmetic, or environmental irritant; or water retention due to menstruation or pregnancy. Persistent fluid-filled bags can signal a more serious problem, such as thyroid, kidney, liver, or heart disease, all of which can cause water retention. I hope this helps you. And good luck.

Fluid retention... sleep on a more elevated pillow. Or its fat that has inserted itself in those pockets.

i dunno but it could be something to do with the fact that our body needs sleep to repair and regenerate itself. its also genetic.