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Medically reviewed by: Melanie L. Pitone, MD

What Is Dehydration?

Dehydration is when there is not enough water in the body. 

What Causes Dehydration?

Dehydration in teens usually is caused by vomiting, diarrhea, or both. It also can happen if a sore throat makes it hard for someone to drink enough. Teens also can get dehydrated in hot weather or when they are very active.

What Are the Signs & Symptoms of Dehydration?

Signs of dehydration include:

  • having a dry or sticky mouth
  • peeing less and darker pee 
  • feeling dizzy and lightheaded

How Is Dehydration Treated?

Most teens with dehydration can be treated at home. To help with dehydration:

  • Drink extra liquids. You can drink water, diluted apple juice, or oral electrolyte solution. Oral rehydration solution (such as Pedialyte, Rehydralyte, or a store brand) has the right amounts of water, sugar, and salt to help with dehydration. You can buy it without a prescription at drugstores or supermarkets.
  • If you are vomiting, take small sips every few minutes. Small sips are less likely to make you vomit again.
  • If you are not vomiting, you can take bigger sips as often as every few minutes.
  • You can also try electrolyte ice pops or ice chips.
  • You can keep eating your regular diet. If you are sick, you may not want to eat at first. But as long you are drinking, it’s OK if you aren’t eating much solid foods.  
  • As you start to feel better and have a better appetite, you can slowly take more of your usual food and drink.
  • Don't drink sports drinks, soda, or full-strength (undiluted) juice. They have too much sugar and can make some symptoms worse.
  • Don’t take medicines for diarrhea or vomiting without talking to your doctor first.

When Should I Call the Doctor?

Call your doctor if you: 

  • can't drink for more than a few hours (for example, if your throat is very sore or you feel sick to your stomach)
  • throw up every time you drink
  • throw up more than a few times in 24 hours
  • have vomit that's bright green, red, or brown
  • haven’t started eating some food within 3–4 days
  • don’t seem to be getting better

Call 911 or have someone take you to the ER if you are having trouble staying awake.

How Can I Prevent Dehydration?

Whenever you get sick, try to drink extra liquids.

In very hot weather or when you do heavy exercise, you need to drink more than usual. Drink extra water before you go outside in hot weather, play sports, or plan to be very physically active. Then, take regular drink breaks (about every 20 minutes) during the activity.

Drinking water before, during, and after playing sports is enough to keep most teens hydrated. Some athletes who exercise for long periods or in very hot weather can benefit from a sports drink that has sugar and electrolytes. Ask your doctor or coach if they think you need to drink sports drinks.

Medically reviewed by: Melanie L. Pitone, MD
Date reviewed: June 2023