Water is essential. You can survive many weeks without food, but you can only survive a few days without water. Your body uses water to digest food, lubricate your joints, move nutrients around your body, and more. The body also loses water through its metabolic byproducts, including:
- Exhaled breath
- Stools (bowel movements)
In order for your body to work, you must drink water and restore any fluids you lose.
What are 5 reasons to drink water?
Maintain normal blood pressure
Your body is made of about 60% water. Most of the water is inside your cells, but some is also between your cells and in your blood. The water moves between these to keep your body in balance.
When you’re dehydrated, your blood volume lowers. This means your blood grows thicker and less diluted, and the total amount of blood circulating in your body decreases. This can cause your heart rate to go up but your blood pressure to fall. Dehydration can also cause sodium (salt) levels to rise in your blood. The salts are lost through sweat, urination, and other forms of fluid loss. This can cause your blood pressure to go up.
Both low and high blood pressure are symptoms of dehydration, depending on which conditions apply most strongly. Staying hydrated can help normalize blood pressure.
Maintain electrolyte balance
You also have electrolytes dissolved in your blood and fluids. These include sodium, potassium, and chloride, which are all various types of salts. These keep your blood at the right pH and are necessary for your nerves and muscles to work properly.
Your body tightly regulates the balance between water and electrolytes in these fluids to keep them at the right concentration. When you don’t have enough water in your cells, your body will move salts out, to bring the water concentration. Your metabolism works almost like a balance scale. This balance has to be right for your body to function.
Your kidneys also filter extra water and electrolytes out of your blood and into your urine. If you don’t have enough water, your brain will signal your kidneys to release hormones. This tells your body to absorb more water and electrolytes, so you will urinate less.
Drinking enough water is a simple way to help keep this careful balance in check.
Regulate body temperature
Water also helps regulate your body temperature. It controls your temperature by dissipating heat. When your body is too hot, water moves to the skin, causing you to sweat. The sweat evaporating from your skin helps cool you down.
As food moves through your colon, it absorbs water and nutrients and makes waste. Your colon then contracts and pushes waste through toward your rectum for a bowel movement.
If you don’t drink enough water, food can move too slowly. The longer it stays there, the more water your colon absorbs. This can cause stool to become hard, lumpy, and difficult to move, leading to constipation. Drink water to help make sure you have regular and easy bowel movements.
Improve your brain
Your brain is made of about 80% water. Too little water can cause mood changes, confusion, and unclear thinking. Even mild dehydration can lower your alertness, concentration, and short-term memory. Drink enough water every day to stay sharp.
How much water you should drink
Water intake varies for each person. Generally, healthy people should drink between 4 and 6 cups of water every day, but there are times you may need more or less.
It’s possible to drink too much water. This can make you sick. The condition can happen if you take certain kinds of medications, or you have liver, kidney, heart, or thyroid disease.
If you exercise and sweat a lot, or have a fever, you will need to drink more water than usual. This is because you lose a lot of fluids as your body tries to keep you cool. It's important to replenish what you lose.
Older people also need to pay attention to how much they drink. This is because you lose your sense of thirst as you age and are more likely to become dehydrated.
Does tea count as water?
People often say that tea and coffee cause dehydration because they are diuretics, meaning they make you urinate. Research does show that caffeine can cause you to urinate more often in the short term, but it doesn’t lead to dehydration. If you enjoy tea or coffee, you can count it toward some of your daily water intake.
Tips to help drink more water
If you struggle to drink water, there are ways to make it easier. Try these hacks:
- Swap juices and sodas for water
- Carry a reusable water bottle with you
- Add a slice of lime to your water
- Drink sparkling water
- Serve water during meals
- Drink throughout the day
If you’re not sure about how much water you need, or you feel thirsty all the time no matter how much you drink, talk to your doctor.
Health Solutions From Our Sponsors
Harvard Medical School Harvard Health Publishing: "How much water should you drink?"
Harvard T.H. Chan: "School of Public Health: Water."
JOHNS HOPKINS MEDICINE: "Constipation."
Merck Manual Consumer Version: "Overview of Electrolytes."
Nutrition Reviews: "Water, Hydration and Health."
The Heart Foundation: "The Importance of Water."
West Kentucky University: "The importance of hydration."
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