Water and Hydration
Quick answer
Water supports temperature control, circulation, digestion, waste removal and chemical reactions. Hydration needs vary with environment, activity, health, pregnancy, age and food intake.
Water comes from more than glasses
Drinks contribute most, but fruit, vegetables, soups and other foods also contain water.
Needs change
Heat, exercise, fever, vomiting, diarrhea and some health conditions can change fluid needs.
Water is a useful default
Choosing water regularly supports hydration without adding sugar or calories, although other beverages and foods can contribute fluid.
A person eating soup, yogurt, fruit and vegetables may obtain more water from food than someone eating mostly dry foods. Counting glasses alone misses that difference.
Key terms
| Hydration | Having sufficient body water for normal function. |
|---|---|
| Dehydration | A state in which water loss exceeds replacement. |
| Electrolyte | A charged mineral such as sodium or potassium. |
| Total water | Water from beverages plus food. |
Common mistakes
- Believing everyone needs exactly eight glasses of water a day.
- Ignoring fluid from foods and other beverages.
- Assuming thirst and urine colour are perfect medical tests. They are practical clues, not diagnoses.
Practical takeaway
Drink regularly, respond to thirst and increase fluids when heat, exercise or illness raises losses. People with medical fluid restrictions need individualized advice.