The basic causes of dehydration are not taking in enough water, losing too much water, or a combination of both. Additional causes of dehydration include:
• Diarrhea – the most common cause of dehydration and related deaths. The large intestine absorbs water from food matter, and diarrhea prevents this from happening.
• Vomiting – leads to a loss of fluids and makes it difficult to replace water by drinking it.
• Sweating – the body’s cooling mechanism releases a significant amount of water. Hot and humid weather and vigorous physical activity can further increase fluid loss from sweating.
• Diabetes – high blood sugar levels cause increased urination and fluid loss. Tips for handling summer heat for people with diabetes.
• Frequent urination – usually caused by uncontrolled diabetes, but also can be due to alcohol and medications such as diuretics, antihistamines, blood pressure medications, and antipsychotics.
• Burns – blood vessels can become damaged, causing fluid to leak into the surrounding tissues.