Staying Hydrated in the Heat – Warning!
We often hear that we should drink more water. It’s crucial to keep the body hydrated throughout the course of a day, not to mention essential for weight loss. What we don’t hear about very often is that too much water consumption can have less than desirable effects.
Drinking a large volume of water very quickly can result in water over-hydration of the body.
When a person consumes too much water too quickly, the kidneys cannot flush it out of the blood fast enough. The blood becomes over-saturated or waterlogged. The water is then drawn to other regions of the body that have high salt concentrations. When the water enters cells inappropriately, they swell. This can happen in the lungs, the organs and the brain.
Lower salt concentration in the blood is known as Hyponatremia. Normal sodium levels in the body are between 135 and 145 mEq/L. When the salt in the blood lowers rapidly, it results in water entering cells and expanding those cells. While some cells can expand safely, the cells in the brain have no place to expand safely because of the skull. Swelling in the brain can become an issue.
Symptoms and Consequences
The symptoms of water over-hydration include nausea, vomiting, headache and confusion. The swelling in the brain contributes to most of the symptoms consistent with hyponatremia. A person suffering from over-hydration can rapidly go from the initial stages of nausea, headache and confusion to a more serious issue. This happens because the cells in the lungs can fill with excess water making it difficult, or eventually impossible to breathe.
How much is too much? Professional athletes know that they must consume water slowly to avoid water over-hydration. Casual athletes who exert themselves infrequently assume that they must drink excessive amounts of water when they are sweating profusely. During heat waves, people drink excessive amounts of water to replace what is lost. These two groups are at the highest risk for water over-hydration.
It’s essential to keep a healthy balance of water and sodium in the body. Many people are so concerned about hydration that they will drink water in anticipation of physical activity. Kidneys in healthy adults are able to process 1 liter of fluid per hour. As long as this is kept in mind by athletes and those who are under extreme stress or in severe heat and humidity, they should be fine.