Water and Fluid Needs

Why are fluids important?

Our bodies are 60 to 70% water. Most parts of the body contain water, including the brain, blood, and muscles. You need the right amount of liquid each day to keep your body working properly. The body needs water to:

  • Control body temperature
  • Remove wastes (through urine and bowel movements)
  • Carry nutrients (food) and oxygen to cells
  • Keep minerals and fluid balanced
  • Cushion joints

How does the body lose fluid?

Your body loses fluids through breathing, sweating and urination. The body can normally keep liquid and salts and minerals in balance by controlling how thirsty you feel or how much water you lose when you urinate or have bowel movements. If you are sweating or urinating more, or have diarrhea or loose bowel movements, your body loses more fluid. You can also lose fluid if you take medicines such as diuretics.

When you lose a lot of fluid, you need to drink more to replace what you have lost. If you don’t drink enough, your body takes fluids from your tissues, muscles, and organs. This makes them not work as well.

Not getting enough fluids to drink can be a serious problem. Even mild dehydration may cause constipation as well as other problems.

What are signs of the need for more fluids?

Some of the signs that you may need more fluids are:

  • Thirst or a dry mouth and tongue
  • Flushed face
  • Dry, warm skin
  • Small amounts of dark yellow urine
  • Weakness, lack of energy, dizziness
  • Cramping in the arms and legs
  • Headache

Thirst is not a good sign that your body needs more fluids. Many people, especially the elderly, may not feel thirsty even if they are dehydrated. A quick way to check that you are getting enough fluids is to look at the color of your urine. The urine should be pale yellow. If your urine is dark yellow or has a strong odor or if you go to the bathroom less than 4 times a day, you probably need to drink more fluids.

How much should I drink?

Ask your healthcare provider about how much fluid you should drink each day. How much you should drink depends on:

  • Your age and body size
  • What you eat (Foods contain different amounts of water.)
  • How active you are (The more active you are, the more water you need.)
  • The weather (The hotter the weather, the more water you need.)
  • Your health (If you have heart failure or kidney disease, you may need to limit fluids and salt. Check with your healthcare provider about drinking sports fluids such as Gatorade if your diet is restricted or when you are taking prescription medicines.)
  • Whether you are a man or woman (Men usually need more water than women do because they have more lean muscle.)
  • What medicines you take (Some medicines, such as diuretics, cause your body to lose water.)

What fluids should I drink?

Water is the best fluid to drink. You can also drink tea, coffee, flavored water, or fruit juices as part of your daily fluids.

Here are some tips to get more fluids in your diet:

  • Drink plenty of fluids throughout the day.
  • Drink more fluids whenever you are vomiting or have diarrhea.
  • Drink extra fluids before and after you exercise. Drink 4 to 6 ounces of water for every 15 minutes of strenuous exercise.
  • Have more fresh fruits, fresh vegetables, and soups with your meals.
  • Keep a glass of water to drink while you are watching TV, working on the computer or relaxing.
Developed by RelayHealth.
Adult Advisor 2015.1 published by RelayHealth.
Last modified: 2014-07-23
Last reviewed: 2014-07-23
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright ©1986-2015 McKesson Corporation and/or one of its subsidiaries. All rights reserved.

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