SymptomsBy Mayo Clinic staff
Mild to moderate dehydration is likely to cause:
- Dry, sticky mouth
- Sleepiness or tiredness — children are likely to be less active than usual
- Decreased urine output — no wet diapers for three hours for infants and eight hours or more without urination for older children and teens
- Few or no tears when crying
- Dry skin
- Dizziness or lightheadedness
Severe dehydration, a medical emergency, can cause:
- Extreme thirst
- Extreme fussiness or sleepiness in infants and children; irritability and confusion in adults
- Very dry mouth, skin and mucous membranes
- Lack of sweating
- Little or no urination — any urine that is produced will be dark yellow or amber
- Sunken eyes
- Shriveled and dry skin that lacks elasticity and doesn't "bounce back" when pinched into a fold
- In infants, sunken fontanels — the soft spots on the top of a baby's head
- Low blood pressure
- Rapid heartbeat
- Rapid breathing
- No tears when crying
- In the most serious cases, delirium or unconsciousness
Unfortunately, thirst isn't always a reliable gauge of the body's need for water, especially in children and older adults. A better indicator is the color of your urine: Clear or light-colored urine means you're well hydrated, whereas a dark yellow or amber color usually signals dehydration.
When to see a doctor
If you're a healthy adult, you can usually treat mild to moderate dehydration by drinking more fluids, such as water or a sports drink (Gatorade, Powerade, others).
Get immediate medical care if you develop severe signs and symptoms such as extreme thirst, a lack of urination, shriveled skin, dizziness and confusion.
Treat children and older adults with greater caution. Call your family doctor right away if your loved one:
- Develops severe diarrhea, with or without vomiting or fever
- Has bloody stool
- Has had moderate diarrhea for three days or more
- Can't keep down fluids
- Is irritable or disoriented and much sleepier or less active than usual
- Has any of the signs or symptoms of mild or moderate dehydration
Go to the nearest hospital emergency room or call 911 or your emergency medical number if you think a child or older adult is severely dehydrated. You can help prevent dehydration from becoming severe by carefully monitoring someone who is sick and giving fluids, such as an oral rehydration solution (Pedialyte, others) at the first sign of diarrhea, vomiting or fever and by encouraging children to drink plenty of water before, during and after exercise.
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