Skip to Content
Home > Health Information > Health Library > Dehydration
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.
Babies and small children have an increased chance of becoming dehydrated because:
Older adults have an increased chance of becoming dehydrated because they may:
Watch babies, small children, and older adults closely for the early symptoms of dehydration anytime they have illnesses that cause high fever, vomiting, or diarrhea. These are the early symptoms of dehydration:
Check your symptoms to decide if and when you should see a doctor.
Many things can affect how your body responds to a symptom and what kind of care you may need. These include:
You have answered all the questions. Based on your answers, you may be able to take care of this problem at home.
You can get dehydrated when you lose a lot of fluids because of problems like vomiting or fever.
Symptoms of dehydration can range from mild to severe. For example:
Severe dehydration means:
Moderate dehydration means:
Mild dehydration means:
Babies can quickly get dehydrated when they lose fluids because of problems like vomiting or fever.
Shock is a life-threatening condition that may occur quickly after a sudden illness or injury.
Babies and young children often have several symptoms of shock. These include:
A baby that is extremely sick:
A baby that is sick (but not extremely sick):
Shock is a life-threatening condition that may quickly occur after a sudden illness or injury.
Adults and older children often have several symptoms of shock. These include:
Many prescription and nonprescription medicines can cause dehydration. A few examples are:
Based on your answers, you may need care soon. The problem probably will not get better without medical care.
Based on your answers, you need emergency care.
Call911or other emergency services now.
Based on your answers, you may need care right away. The problem is likely to get worse without medical care.
In the early stages, you may be able to correct mild to moderate dehydration with home treatment measures. It is important to take action to prevent dehydration.
If you become mildly to moderately dehydrated while working outside or exercising:
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.
Don't wait until you see signs of dehydration in your baby. These signs include your baby being thirstier than usual and having less urine than usual.
Call your doctor if any of the following occur during home treatment:
The following tips may help you prevent dehydration.
Prompt home treatment for diarrhea, vomiting, or fever will help prevent dehydration.
To prepare for your appointment, see the topicMaking the Most of Your Appointment.
You can help your doctor diagnose and treat your condition by being prepared to answer the following questions:
Current as of: June 26, 2019
Author: Healthwise StaffMedical Review: William H. Blahd Jr. MD, FACEP - Emergency MedicineKathleen Romito MD - Family MedicineAdam Husney MD - Family Medicine
Current as of:
June 26, 2019
Medical Review:William H. Blahd Jr. MD, FACEP - Emergency Medicine & Kathleen Romito MD - Family Medicine & Adam Husney MD - Family Medicine
To learn more about Healthwise, visit Healthwise.org.
© 1995-2019 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.
You'll find Decision Points to help you answer questions about:
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.
See important information from Billings Clinic on Non-discrimination and Interpreter Services.
Billings Clinic is proud to be an equal opportunity/affirmative action (EOE/AA) e-verify employer.