Your body may lose too much fluids from:
• Vomiting or diarrhea
• Excessive urine output, such as with uncontrolled diabetes or diuretic use
• Excessive sweating (From exercising)
• Fever

You might not drink enough fluids because of:
• Nausea
• Loss of appetite due to illness
• Sore throat or mouth sores

Dehydration in sick children is often a combination of both -- refusing to eat or drink
anything while also losing fluid from vomiting, diarrhea, or fever.

 • Vomiting  • Excessive urine output  • Excessive sweating  • Fever