Dehydration: Symptoms, Causes & Treatment

Dehydration is a condition that occurs when the body loses more fluids than it takes in, so it does not have enough water to perform its normal functions. Water is essential for nearly all body processes: regulating temperature, transporting nutrients, and organ function, so its shortage quickly affects the whole body.

Dehydration happens either from low fluid intake or from increased loss, and the most common causes are diarrhea and vomiting (especially in children), fever, profuse sweating in hot weather or during exercise, and frequent urination as in uncontrolled diabetes. Its danger is greater in young children because their bodies lose fluids quickly, and in older adults whose sense of thirst may be reduced.

Dehydration severity ranges from mild, treatable at home by drinking fluids, to severe and life-threatening, needing intravenous fluids in hospital. Among its most important signs are thirst, dry mouth, reduced urine amount and dark color, dizziness, and fatigue, and in children dry mouth, fewer tears when crying, sunken eyes, and fewer wet diapers. Prevention is simple and effective: drinking enough water daily, increasing it in heat, exercise, and illness, and using oral rehydration solutions with diarrhea and vomiting to replace salts and fluids together.

• Thirst and dry mouth.
• Reduced urine amount and dark color.
• Dizziness, fatigue, and headache.
• In children: fewer tears, sunken eyes, fewer wet diapers, lethargy.

• Low fluid intake.
• Diarrhea and vomiting (most common causes in children).
• Fever and profuse sweating in heat and exercise.
• Frequent urination as in uncontrolled diabetes.

• Young children and infants.
• Older adults.
• Hot weather and strenuous exercise.
• Illnesses with fever, diarrhea, or vomiting.

• Clinical assessment of symptoms and dehydration signs.
• Blood and urine tests to assess severity and salts when needed.

Mild to moderate dehydration

• Drinking fluids gradually, and oral rehydration solutions especially with diarrhea and vomiting.

Severe dehydration

• Intravenous fluids in hospital, an emergency especially for children and older adults.

This content is educational and does not replace medical advice.

• Circulatory collapse (shock) in severe dehydration.
• Kidney failure and seizures from salt imbalance.
• Heat stroke in hot weather.

• Drinking enough water daily.
• Increasing fluids in heat, exercise, and illness.
• Oral rehydration solutions early with diarrhea and vomiting.
• Monitoring children and older adults, especially in summer.