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.
Use the Check Your Symptoms section to decide if and when you should see a doctor.
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
- ¼ teaspoon (1.25 g) salt substitute (potassium-based), such as Lite Salt or Morton Salt Substitute
- 2 tablespoons (30 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, the amount of fluid you normally use in the formula should be enough to replace lost fluids. Check with your child's doctor if you think you need to feed your baby 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:
- Drink plenty of water before, while, and after you
are active. This is very important when it’s hot out and when you do intense
exercise. You can drink water or
- Drink plenty of 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.
Preparing For Your Appointment
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?
|Author||Jan Nissl, RN, BS|
|Editor||Susan Van Houten, RN, BSN, MBA|
|Associate Editor||Tracy Landauer|
|Primary Medical Reviewer||Martin Gabica, MD - Family Medicine|
|Primary Medical Reviewer||William M. Green, MD - Emergency Medicine|
|Specialist Medical Reviewer||H. Michael O'Connor, MD - Emergency Medicine|
|Specialist Medical Reviewer||William H. Blahd, Jr., MD, FACEP - Emergency Medicine|
|Last Updated||June 30, 2009|
Last Updated: June 30, 2009