Five signs that you could be dehydrated

Getting enough fluids to stay hydrated is essential for the body to operate at its best. Water makes up about 60 percent of our body weight and we depend on water to survive. Water helps to remove waste and toxins, regulate body temperature, lubricate joints, helps in proper digestion, and many more things to help our organs to work properly.

Throughout the day, we naturally use and lose water — when we urinate, sweat or have a bowel movement, even just by breathing. The body can't make any water itself and must rely on what we drink to replenish what is lost.

Dehydration happens when you lose more water than you take in. Mild dehydration can drain your energy and make you feel tired. Severe dehydration can affect the brain, cause your blood pressure to drop, and also cause kidney failure.

One sign that you are dehydrated is that you feel thirsty, but there are also some other less obvious ways that your body is trying to tell you that you've gone too long without water.

1. You have a headache. While there is no certain explanation for why headaches occur with dehydration, a working theory is that the meninges, the membrane layers that protect your brain and spinal cord, can sense pain when dehydration causes fluid to shift out of the brain, putting pressure on the meninges. A headache occurs as a result and could be a possible sign that you are water-deprived.

2. You have bad breath. Saliva can fight odor-causing germs in the mouth, and you need water to make saliva. If you are dehydrated you may not have enough water in your body to make saliva, and this can cause bad breath. Maybe reach for a glass of water next time rather than a breath mint.

3. You feel constipated. Being constipated means having less than three bowel movements for week, or less than your usual, making you feel bloated and uncomfortable. One of the culprits for constipation is dehydration, as water aids in digestion.

4. You're in a bad mood. While lack of sleep and hunger (being "hangry") are largely responsible for a negative mood, dehydration can also play a role and can make you feel irritable. So next time you feel like snapping at those around you, it may have less to do with their behavior and more to do with your need for water.

5. You feel hungry. You could really be hungry and may need to eat something, but there are times when you may feel cravings or can't figure out why you feel hungry when it's not the usual time for you to eat. Try drinking a glass of water and wait about 15 minutes. This may satisfy that craving or urge to snack.

So how much should you drink? You've probably heard the advice to drink eight glasses of water a day, with each glass containing eight ounces or 250 milliliters. Eight glasses of water easy to remember, and it's a reasonable goal.

But there is no single rule to follow to know how much you need to drink and individual needs depend on many factors — your level of activity, where you live and if you have any other health problems. If you are unsure, you can always ask doctor how much water is right for you.