When Do You Need to Drink More Water?

Your body contains more water than anything else, about 60 percent of your total body weight. Water helps regulate your body temperature, transports nutrients, and helps remove waste. Every day you lose water when you breathe, sweat, urinate, and defecate, and that water needs to be replenished.

How Much Water Do You Need?

The big question is how much water do you need to drink every day? Although that's a simple question, it doesn't have an easy answer. It depends on some environmental and physical factors that can change every day. Also, it's not just the water you drink—about 20 percent of your water intake comes from the foods you eat. The remaining 80 percent comes from beverages, including water, coffee, tea, milk, and anything liquid.

The Institute of Medicine of the National Academy reviewed years of research evidence on adequate water intake and has the following recommendations:

Men: 13 cups (about 10.5 cups from beverages)
Women: 9 cups (about 7 cups from beverages)
Pregnant women: 10 cups (about 8 cups from beverages)
Breastfeeding women: 13 cups (about 10.5 cups from beverages)

How Do You Know If You're Drinking Enough Water?

Most people can gauge their water intake by looking at urine color. If you're getting enough water, your urine will be pale yellow, and you'll urinate several times a day. Urine color doesn't work for everyone. Taking dietary supplements that contain riboflavin will make your urine bright yellow, and certain medications can change the color of your urine, as well. And if you have any kidney problems or other heath conditions you should talk to your health care provider about how much water to drink.

If You're Thirsty

Glasses Of Water — Nawarit Rittiyotee / EyeEm / Getty Images

Thirst is the desire to drink something. It can be triggered by the loss of fluid volume in and around cells and in the blood. Thirst is your body's way of saying you need water to avoid dehydration.

Thirst has a behavioral component as well and can be triggered by aromas and flavors, so just thinking about your favorite beverage can make you thirsty. It's also important to note that older people often have problems with the thirst mechanism and may not feel thirsty even when they're dehydrated.

If You Have Bad Breath and Dry Mouth

There are some things that can cause bad breath like eating onions or garlic. But another potential reason is a lack of normal saliva production. Even mild dehydration can reduce saliva flow so if your bad breath is accompanied by a dry mouth, drinking more water throughout the day may help. Keep a glass of water by your bedside for nighttime relief, too.

If You Can't Think Straight

Water is essential for brain function. Studies show that a loss of about two percent of your body fluid can cause a decline in mental function, so if you're having trouble concentrating, it may be time for a water break.

If You're Physically Active

Increased activity like exercise or physical labor can increase the amount of fluid lost when you sweat. It's best to drink two to three cups of water before your activity begins and drink about one cup of water every 15 minutes or so while you're active. You might need even more if you're working or exercising in extreme temperatures.

If You're in a Hot Area

Water is essential for regulating your body temperature, so if you're outside on a hot day or stuck inside without air conditioning, you're going to need more water as the heat causes you to sweat more. Even if you're not active, spending the day in 90-degree temperature conditions could more than double your fluid requirement. And even more if you're physically active.

If You're at a High Elevation

Air pressure is reduced at higher elevations and compared to being at sea level, people who live at 4,000 feet generally lose about eight ounces more fluid every day, mostly because of changes in respiration. The higher you go, the greater potential for fluid loss, so be sure to bring extra water if you're going for a hike in the mountains.

If You Have a Fever

If you're sick with a fever, letting yourself get dehydrated isn't going to help, and it may make the fever worse. Sip water or other fluids to keep yourself hydrated. Also, see your health care provider if the fever lasts more than two days or you have other symptoms that don't go away.

If You Have Diarrhea

Diarrhea can happen for a variety of reasons, including infections, irritable bowel syndrome, and inflammatory bowel disorders. But whatever, the cause, diarrhea can lead to dehydration. Drink extra fluids while you have diarrhea, and after, to remain hydrated.

If You Have a Hangover

Drinking too much alcohol will lead to a hangover the next day. While one or two alcoholic beverages shouldn't cause a problem, overindulging can result in dehydration, inflammation, a headache, and stomach irritation. Drink plenty of water while you're recuperating. And next time, drink water while you're partying – it may slow down your alcohol consumption.

If You're Pregnant

Women who are pregnant need about ten cups of fluid every day. Some women retain extra fluid during their pregnancy and have some swelling, but that doesn't reduce the need for water. If you're pregnant, talk to your doctor about how much water you need every day.

If You're Breastfeeding

Breastmilk is mostly water, so you'll need to drink extra water while you're breastfeeding. The Institute of Medicine recommends all breastfeeding moms consume about 13 cups of fluids every day. It doesn't all have to be water because any healthy beverages will fulfill your fluid need.

What About Caffeine?

Caffeine is a diuretic, which means it makes you pee more, but your body adapts to moderate caffeine intake and the amount of water in your cup of coffee, or tea is more than enough to offset any fluid lost. But it's not clear what happens if you consume lots of caffeine without the fluid. There's probably some potential for dehydration if you're gulping down energy drinks and dancing it up all night without drinking extra water.