Symptoms of mild dehydration include:

• Increased thirst.
• Dry mouth and sticky saliva.
• Reduced urine output with dark yellow urine. Your urine may have a strong odor.

Symptoms of moderate dehydration include:

• Extreme thirst.
• Dry mouth with no saliva.
• Dry eyes; no tears.
• Decreased urination, or urinating 3 or fewer times in 24 hours. Urine is dark amber or brown.
• Arms and legs that may feel cool to the touch.
• Feeling very tired, restless, or irritable.
• Lightheadedness that is relieved by lying down.

Whenever you have an illness that causes a high fever, vomiting, or diarrhea, your chance of dehydration increases because your body is losing water more quickly than you can replace it. This is especially true if you are vomiting and are unable to replace lost fluids.

Babies, small children, and older adults cannot replace lost fluids as efficiently as older children and young adults. They should be watched closely for signs of dehydration when they become ill.