Most of the human body is made up of water, with an average of approximately 60%. The exact percentage is slightly different for each of us depending on our age, sex, body type, and physical activity level. For example, babies’ bodies are made up of more water than adults and fat contains less water than muscle.

How does hydration help us stay healthy?

Water is essential for our overall health and is key for performing certain body functions, including:

• Regulating temperature. When you overheat due to a sunny day, strenuous workout, or a fever, your body produces sweat to cool down. Since sweat is mostly made of water, your body needs it to stay hydrated.
• Functioning of muscles and organs. Your body’s cells work best when fully hydrated.
• Controlling weight. Thirst can be mistaken for hunger. Staying hydrated may help us avoid eating when we don’t need to.
• Removing waste. Well-hydrated people usually have regular bowel movements. Constipation can be a sign that you aren’t getting enough water.

Tips to drink more water

People can maintain the right balance of water in their bodies by drinking liquids throughout the day. More may be needed after exercise and in hot weather. Here are some hydration tips from Dr. Leda Ghannad, a sports medicine physician at Midwest Orthopaedics at Rush:

1. Establish reminders to hydrate. Write reminders on sticky notes or enter them into your phone or watch. There are also apps to remind you to drink a pre-determined amount of water. Try it and it’s likely that drinking more water will become a habit.
2. Remind others to drink to thirst. Remind your friends and family that it’s important to drink lots of water each day, especially in the summer or when exercising. We often forget to make hydration a priority but being prompted by you can be a good reminder.
3. DIY fruit-infused water. If you think water tastes a little boring, infuse a pitcher of water with lemon or lime slices, cucumber slices, strawberries, cantaloupe, mint, or other fresh produce. Try filling up reusable bottles with infused water at the beginning of each week or make a whole pitcher for work or home.

How much water should you drink?

The short answer is: It depends.

“I typically recommend that my patients drink eight ounces of water six to eight times a day,” explains Dr. Ghannad “But some may need more or less, depending on their overall health and amount of activity. Illness and certain medications can also affect how much water you need. Ramp it up based upon how much you exercise, the level of intensity, and how hot and dry the weather is.”

Dr. Ghannad warns that drinking excess water can actually be dangerous and lead to conditions like hyponatremia during marathons and marathon training. It’s best to "drink to thirst."

What happens if you don’t drink enough water?

Dehydration happens when your body doesn't have as much water as it needs and can’t function properly. You can experience various stages of dehydration depending on how much fluid is missing from your body.

Signs of mild or moderate dehydration:

• Muscle cramps
• Headache
• Thirst
• Dry or sticky mouth
• Infrequent urination
• Dark yellow urine
• Dry, cool skin

Signs of severe dehydration:

• Infrequent urination or dark yellow urine
• Very dry skin
• Dizziness
• Rapid heartbeat
• Rapid breathing
• Sunken eyes
• Lethargy, confusion, or irritability
• Fainting

If you experience any of these signs or symptoms, drink water right away, contact your physician, or visit an emergency department.