One of the most obvious signs that an individual is becoming dehydrated and needs to receive fluids is dark colored urine. The darker the urine the more dehydrated you are. The body needs the water to safely expel the wastes from your body. When there isn't enough water all you are going to see is the waste. If you are dehydrated you will also begin to urinate much less often.
Fatigue is being more than just a little tired. It is becoming so tired that you begin to feel weak. The more dehydrated you are the more fatigue you will experience. It is important to check your fluid intake as soon as you begin feeling overly tired.
When an adult is in need of fluids they may experience some dizziness. This is mostly noticeable when the adult attempts to stand from a sitting position. The individual may even faint if the dehydration is bad enough or they don't sit back down immediately. To keep from fainting a second time an adult who is experiencing dehydration should drink some water right away.
Cotton mouth is another term for dry mouth. When you become dehydrated you use up all of the water you had previously drank. Your mouth needs water to produce saliva. If it is no longer getting that water you will begin to feel like your mouth is extremely dry because the saliva is drying up. If this happens you must drink some water and chew on some ice chips to keep you mouth moist.
Problems with the Skin
There are two types of problems that can occur with the skin as a result of dehydration. First, you skin become dried out. It is lacking the water it needs to stay moist. If you can pinch your skin and it takes more than a second or two to turn back to normal, you are dehydrated. Second, your skin can become all red. This happens mostly in the face, but can occur elsewhere. If this happens you need to get more fluids in you as soon as possible because your skin will take some time to bounce back. The sooner you get started re-hydrating the sooner you will get your skin back to normal.