Increased thirstThe first and most logical sign is thirst. Your body will always send you signals when you’re deficient in something. For example, when you need food, you feel hunger. When you have a deficiency of some minerals and vitamins, your body will send you other signals. But when you’re dehydrated, you feel increased thirst. And this isn’t a thirst you can satisfy with just one glass of water.
Dry mouthAnother logical sign is dry mouth. Every part of your body needs fluids to function properly. For your mouth, water and other fluids keep the mouth moist. But when you’re dehydrated, your body preserves fluids, and it saves up fluids from non-vital organs like your mouth.
Urine issuesThere are two things that happen when you’re dehydrated that are closely related to your urine. First and foremost, your urine output is decreased. You just can’t pee without fluids. The second sign is the color—your urine is more yellow than normal.
Bad breathAs mentioned previously, when you’re dehydrated, your body saves fluids. And one thing that happens is your body doesn’t produce enough saliva. Saliva is responsible for keeping your breath fresh; it has antibacterial properties, and without it, bacteria will overgrow in your mouth. Think of bad breath as a side reaction from chronic dehydration.
HeadachesLast, but not least of the mild and early signs of dehydration, is a headache. Let’s turn to biology for a second. Your brain is located in a fluid sack. This sack keeps your brain from bumping against the skull. When you’re low on fluids, that fluid sack is depleted. And your brain can push up against some parts of the skull, which in turn, causes headaches. So, drink plenty of water to prevent migraines and headaches.