How to assess dehydration — tips from AboutKidsHealth

Whether it be at soccer games, family barbecues or picnics in the park, the summer months are a great time for kids to participate in outdoor activities and spend time in the sun. However, kids can be prone to dehydration when they are being active in warmer weather. It is important for kids to drink enough water and fluids to stay hydrated in the summertime and avoid getting sick.

AboutKidsHealth has provided information on how parents and caregivers can recognize and assess dehydration so kids can stay healthy while enjoying the end-of- summer temperatures. For more information on dehydration, visit

How do kids become dehydrated?
When we eat and drink, we replace body fluids we have lost through urine, stool, sweat and tears. Dehydration occurs when we drink less fluid than we lose. Children can also get dehydrated when they are ill and lose more fluid than usual through vomiting, diarrhea and fever.

Babies and young children are most at risk for dehydration. Due to their small size, younger children have smaller fluid reserves.

Signs and symptoms of dehydration

If your child is dehydrated, they may show:

  • dry, cracked lips and a dry mouth
  • a decrease in urine output, no urine for 8 to 12 hours, or dark-coloured urine
  • drowsiness or irritability
  • cold or dry skin
  • low energy levels, seeming very weak or limp
  • no tears when crying
  • sunken eyes or sunken soft spot (fontanelle) on baby’s head.

How to assess dehydration

You can measure your child’s dehydration by scoring their symptoms according to their values on the Clinical Dehydration Scale, which is used by health care professionals to assess dehydration. The higher your child’s total score, the more severe their dehydration.

If your child scores between 5 to 8, they have moderate to severe dehydration. In this case, they should go to the doctor or nearest hospital immediately.

If your child scores 1 to 4, they have mild dehydration. Your child can drink oral rehydration solution — such as Gastrolyte or Pedialyte — to replace water and salts they have lost. Oral rehydration solution is better than water or homemade drinks because it will provide a balance of water, sugars, and salts that will help your child absorb fluid. If your baby won’t breastfeed, see a doctor right away.

If your child scores 0, they are not dehydrated and can continue drinking fluids and eating as they normally would. If they are vomiting or have diarrhea, give them 10 mL/kg of oral rehydration solution each time they throw up or have diarrhea.For more information on how to prevent and treat dehydration, visit

AboutKidsHealth is SickKids’ patient-education website and features more than 3,500 articles on a range of paediatric health topics. For more information on dehydration and other topics, please visit