Health Library DehydrationFrom Healthwise

Dehydration occurs when your body loses too much fluid. This can happen when you stop drinking water or lose large amounts of fluid through diarrhea, vomiting, sweating, or exercise. Not drinking enough fluids can cause muscle cramps. You may feel faint. Usually your body can reabsorb fluid from your blood and other body tissues. But by the time you become severely dehydrated, you no longer have enough fluid in your body to get blood to your organs, and you may go into shock, which is a life-threatening condition.

Dehydration can occur in anyone of any age, but it is most dangerous for babies, small children, and older adults.

Dehydration in babies and small children

Babies and small children have an increased chance of becoming dehydrated because:

• A greater portion of their bodies is made of water.
• Children have a high metabolic rate, so their bodies use more water.
• A child's kidneys do not conserve water as well as an adult's kidneys.
• A child's natural defense system that helps fight infection (immune system) is not fully developed, which increases the chance of getting an illness that causes vomiting and diarrhea.
• Children often will not drink or eat when they are not feeling well.
• They depend on their caregivers to provide them with food and fluids.

Dehydration in older adults

Older adults have an increased chance of becoming dehydrated because they may:

• Not drink because they do not feel as thirsty as younger people.
• Have kidneys that do not work well.
• Choose not to drink because of the inability to control their bladders (incontinence).
• Have physical problems or a disease which makes it:
  • Hard to drink or hold a glass.
  • Painful to get up from a chair.
  • Painful or exhausting to go to the bathroom.
  • Difficult to talk or communicate to someone about their symptoms.
• Take medicines that increase urine output.
• Not have enough money to adequately feed themselves.

Watch babies, small children, and older adults closely for the early symptoms of dehydration any time they have illnesses that cause high fever, vomiting, or diarrhea. The early symptoms of dehydration are:

• A dry mouth and sticky saliva.
• Reduced urine output with dark yellow urine.
• Acting listless or easily irritated.

Review the Emergencies and Check Your Symptoms sections to determine if and when you need to see a doctor.

• Shock is present:
  • In a child.
  • In an adult or older child.
• Severe dehydration is present:
  • In a child.
  • In an adult or older child.

If you answer yes to any of the following questions, click on the "Yes" in front of the question for information about how soon to see a health professional.

Review health risks that may increase the seriousness of your symptoms.

	Yes	Does your child have mild to moderate dehydration?
When to See a Doctor See significance of dehydration if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your child's symptoms. Call your health professional immediately if you answer "Yes" to the following question. Yes Does your child have moderate dehydration? Call your health professional today if you answer "Yes" to the following question. Yes Does your child have mild dehydration, and he or she is unable to drink enough to replace lost fluids? You may wait to see if the symptoms improve over the next 24 hours (or specified time period) if you answer "Yes" to the following question. Yes Has your child had mild dehydration for 12 hours or longer, but he or she is able to drink enough to replace lost fluids? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Do you have mild to moderate dehydration?
When to See a Doctor See significance of mild to moderate dehydration if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional today if you answer "Yes" to the following question. Yes Do you have mild to moderate dehydration, and you are not able to drink enough to replace lost fluids? You may wait to see if the symptoms improve over the next 24 hours (or specified time period) if you answer "Yes" to the following question. Yes Have you had mild dehydration for 12 hours or longer, but you are able to drink enough to replace lost fluids? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Do you think that a medicine may be causing your dehydration?
When to See a Doctor See significance of a medicine causing dehydration if you need information to help you answer the question below. Review health risks that may increase the seriousness of your symptoms. Call your health professional today if you answer "Yes" to the following question. Yes Do you think that your dehydration is caused by a medicine? Note: Call the doctor who prescribed the medicine to find out if you should stop taking the medicine or take a different one. An appointment may not be necessary. If you are taking a nonprescription medicine, stop taking the medicine. Call your doctor if you feel you need to continue taking the medicine. If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.

Other Symptoms to Watch For

Do you have any of the following symptoms?

• Vomiting: Go to the topic Nausea and Vomiting, Age 4 and Older or Vomiting, Age 3 and Younger.
• Diarrhea: Go to the topic Diarrhea, Age 12 and Older or Diarrhea, Age 11 and Younger.
• Fever: Go to the topic Fever, Age 4 and Older or Fever, Age 3 and Younger.
• Urinary problems: Go to the topic Urinary Problems, Age 11 and Younger or Urinary Problems, Age 12 and Older.
• Sunburn: Go to the topic Sunburn.
• Muscle cramps or other heat-related illnesses: Go to the topic Heat-Related Illnesses.

If a visit to a health professional is not needed immediately, see the Home Treatment section for self-care information.

In the early stages, you may be able to correct mild to moderate dehydration with home treatment measures. It is important to control fluid losses and replace lost fluids.

Adults and children age 12 and older

If you become mildly to moderately dehydrated while working outside or exercising:

• Stop your activity and rest.
• Get out of direct sunlight and lie down in a cool spot, such as in the shade or an air-conditioned area.
• Prop up your feet.
• Take off any extra clothes.
• Drink a rehydration drink, water, juice, or sports drink to replace fluids and minerals. Drink 2 qt (2 L) of cool liquids over the next 2 to 4 hours. You should drink at least 10 glasses of liquid a day to replace lost fluids. You can make an inexpensive rehydration drink at home. But do not give this homemade drink to children younger than 12. Measure all ingredients precisely. Small variations can make the drink less effective or even harmful. Mix the following:
  • 1 quart (950 ml) water
  • ½ teaspoon (2.5 g) baking soda
  • ½ teaspoon (2.5 g) table salt, or ¼ teaspoon (1.25 g) salt substitute (such as "Lite Salt," which is potassium-based)
  • 3 to 4 tablespoons (45 to 60 g) sugar

Rest and take it easy for 24 hours, and continue to drink a lot of fluids. Although you will probably start feeling better within just a few hours, it may take as long as a day and a half to completely replace the fluid that you lost.

Children ages 1 through 11

• Make sure your child is drinking often. Frequent, small amounts work best.
• For children with dehydration, an oral rehydration solution (ORS), half-strength orange juice, or plain water (if the child is eating food) may be used to replace lost fluids.
• Allow your child to drink as much fluid as he or she wants. Encourage your child to drink extra fluids or suck on Popsicles. Children between the ages of 4 and 10 should drink at least 6 to 10 glasses of liquids to replace lost fluids.
• Cereal mixed with milk or water may also be used to replace lost fluids.

Newborns and babies younger than 1 year of age

Don't wait until dehydration develops to replace lost fluids. Offer fluids to your baby often.

• If you breast-feed your baby, nurse him or her more often.
• If you use a bottle to feed your baby, feed him or her more often.
• Use an oral rehydration solution (ORS) if mild or moderate dehydration develops. The amount of ORS your baby needs depends on his or her weight and how dehydrated he or she is. You can give the ORS in a dropper, spoon, or bottle.
• If your baby has started eating cereal, you may replace lost fluids with cereal. You also may feed your baby strained bananas and mashed potatoes if your child has had these foods before.

Symptoms to Watch For During Home Treatment

Use the Check Your Symptoms section to evaluate the symptoms if any of the following occur during home treatment:

• More serious dehydration develops.
• Decreased alertness develops.
• You become dizzy, lightheaded, or feel like you might faint when you rise from lying to sitting, or from sitting to standing.
• Decreased urination develops.
• Symptoms become more severe or frequent.

The following tips may help you prevent dehydration.

• Prompt home treatment for illnesses that cause diarrhea, vomiting, or fever will help prevent dehydration. Review the home treatment recommendations for other symptoms you may have. Go to the following topics:
  • Diarrhea, Age 12 and Older
  • Diarrhea, Age 11 and Younger
  • Fever, Age 4 and Older
  • Fever, Age 3 and Younger
  • Nausea and Vomiting, Age 4 and Older
  • Vomiting, Age 3 and Younger
  • Urinary Problems, Age 11 and Younger
  • Urinary Problems, Age 12 and Older
  • Sunburn
  • Heat-Related Illnesses
• To prevent dehydration during hot weather and exercise, drink 8 to 10 glasses of fluids, such as water or rehydration drinks each day.
  • Drink extra water before, during, and after exercise.
  • Take a container of water or sports drink with you when you exercise, and try to drink at least every 15 to 20 minutes.
  • Use a sports drink if you will be exercising for longer than 1 hour.
• Encourage your child to drink extra fluids or suck on Popsicles. Children between the ages of 4 and 10 should drink at least 6 to 10 glasses of liquids to replace lost fluids.
• Do not drink coffee, colas, or other drinks that contain caffeine. They increase urine output and make you dehydrate faster.
• Avoid high-protein diets. If you are on a high-protein diet, make sure that you drink at least 8 to 12 glasses of water each day.
• Do not drink alcohol, including beer and wine. They increase dehydration and make it difficult to make good decisions.
• Do not take salt tablets. Most people get plenty of salt in their diets. Use a sports drink if you are worried about replacing minerals lost through sweating.
• Stop working outdoors or exercising if you feel dizzy, lightheaded, or very tired.
• Wear one layer of lightweight, light-colored clothing when you are working or exercising outdoors. Change into dry clothing as soon as you can if your clothes get soaked with sweat. Never exercise in a rubber suit.

To prepare for your appointment, see the topic Making the Most of Your Appointment

You can help your doctor diagnose and treat your condition by being prepared to answer the following questions:

• When did the dehydration problem start?
• What activities cause you to feel dehydrated?
• Have you had a hard time getting enough fluids or holding down fluids because of vomiting, diarrhea, or fever?
• If vomiting or diarrhea are causing your dehydration, how many episodes have you had in the last 24 hours? When was the last episode of vomiting or diarrhea?
• Has nausea kept you from taking in enough fluids?
• What prescription and nonprescription medicines do you take?
• Have you been using water pills (diuretics) or laxatives?
• What have you tried so far to help you rehydrate?
• What activities related to sports or work make your symptoms better or worse?
• Do you have any health risks?

• Abdominal Pain, Age 11 and Younger
• Abdominal Pain, Age 12 and Older
• Appendicitis
• Diarrhea, Age 11 and Younger
• Diarrhea, Age 12 and Older
• Fever, Age 3 and Younger
• Fever, Age 4 and Older
• Irritable Bowel Syndrome (IBS)
• Nausea and Vomiting, Age 4 and Older
• Pregnancy
• Shock
• Vomiting, Age 3 and Younger

Author:	Jan Nissl, RN, BS	Last Updated: July 6, 2007
Medical Review:	William M. Green, MD - Emergency Medicine H. Michael O'Connor, MD - Emergency Medicine
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