Dehydration

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Definition Symptoms Causes Risk factors When to seek medical advice

Tests and diagnosis Complications Treatments and drugs Prevention

Definition

Dehydration occurs when you lose more fluid than you take in and your body doesn't have enough water and other fluids to carry out its normal functions. If lost fluid remains unreplenished, you may suffer serious consequences.

Common causes of dehydration include intense bouts of diarrhea, vomiting, fever or excessive sweating. Inadequate intake of water during hot weather or exercise also may deplete your body's water stores. Anyone may become dehydrated, but young children, older adults and people with chronic illnesses are most at risk. Mild dehydration can cause symptoms such as weakness, dizziness and fatigue. Severe dehydration is a life-threatening medical emergency.

You can usually reverse mild to moderate dehydration by increasing your intake of fluids, but severe cases need immediate medical treatment. The safest approach is not to become dehydrated in the first place. You can do that by monitoring your fluid loss during hot weather, illness or exercise, and drinking enough liquids to replace what you lose.

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Symptoms