Droopiness can signal dehydration and there’s an easy way to check if you have a problem. Pinch your skin. If it doesn’t bounce back quickly, you may not be getting enough water. Proper hydration naturally plumps skin cells to prevent sagging — so not sipping enough water can cause drooping. Other signs of dehydration include dry mouth and lingering fatigue. To stop the droop, make sure you’re drinking enough water. For optimal health, experts suggest eight glasses a day.