You may pass little or no urine for 12 or more hours.
You may not feel alert or be able to think clearly.
You may be too weak or dizzy to stand.
You may pass out.
Severe dehydration is a medical emergency and requires emergency treatment. Call 911 or other emergency services immediately.
Moderate dehydration means:
You may be a lot more thirsty than usual.
Your mouth and eyes may be drier than usual.
You may pass little or no urine for 8 or more hours.
You may feel dizzy when you stand or sit up.
Mild dehydration means:
You may be more thirsty than usual.
You may pass less urine than usual.
Mild to moderate dehydration is treated at home by drinking more fluids. Treatment for moderate to severe dehydration may include IV fluids and a stay in the hospital.
Dehydration is very dangerous for babies, small children, and older adults. It is most dangerous for newborns. Watch closely for early symptoms anytime there is an illness that causes a high fever, vomiting, or diarrhea.
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & Adam Husney, MD - Family Medicine