The Dangers Of Overhydration

We’ve spoken before about the importance of staying properly hydrated, and it’s something we do during the day at our Remuera physio clinic. It helps us stay alert and focused as we provide our physiotherapy services, and we obviously recommend that all of our clients do the same thing.

The New Zealand Nutrition Foundations recommends that adults should take in about 1.5 to 2 litres of fluid each day, while children should be drinking 1 to 1.5 litres. If you are exercising or playing a sport, you will need to drink more. A good test that you are properly hydrated is that you go to the toilet regularly and your urine is a pale yellow colour – if it is dark yellow you are not drinking enough water while if it looks like water, you are having too much fluid. And too much fluid is not a good thing.

Overhydration might not be as common as dehydration but the symptoms are the same: nausea and vomiting, headache, fatigue, weakness, a loss of balance and an unsteady gait. Because the symptoms of overhydration and dehydration are so similar, many people make the mistake of drinking even more fluids – and that just makes things worse.

We need electrolytes like sodium, potassium, chloride, and magnesium in our bloodstream. It’s these things that keep our muscles contracting, our nervous system functioning, and our body’s acid-base levels in balance. It’s a delicate ratio and when you drink too much fluid, it becomes very unbalanced. This is of most concern when excessive fluid dilutes the amount of sodium in the bloodstream, leading to dangerously low levels. This is known as hyponatremia, and when it occurs, the body’s water levels rise and cells begin to swell. This can cause many health problems, ranging from mild to life-threatening.

Hyponatremia is most common in athletes who drink too much fluid before, during and after an event. A survey of participants in the 2002 Boston Marathon found that 13% of the runners were suffering from hyponatremia from taking in more than they needed before and during the race. In a bid to try and keep ahead of their thirst, they drank more fluid than was required with unsurprising results.

Fortunately, hyponatremia is not an issue for most of us but it does remind us that we should hydrate in the right way. A regular small amount of water rather than huge amounts on an infrequent basis are best. Drink when you’re thirsty instead of trying to stay ahead of your thirst. While we all understand the need to stay hydrated, it’s about getting the balance right – not too much, and not too little. At our physiotherapy clinic near Remuera, that is something we strive to do each day.