By Sylvia Chebet
Ashley Summers, an American mother of two, was holidaying with her family in Indiana's Lake Freeman over the Fourth of July weekend when she felt dehydrated and giddy. Shortly after drinking four bottles containing nearly two litres of water in 20 minutes, she passed out. Her family took her to hospital, but she never regained consciousness.
The medically determined cause of death came as a shock. Ashley, it transpired, had died of a little-known condition called water toxicity or intoxication, brought on by drinking too much water.
Unbeknownst to most people who have grown up hearing about the benefits of frequent hydration, "there is indeed such a thing as overhydration", the unit head of water and sanitation at the World Health Organisation (WHO), Bruce Gordon, tells TRT Afrika.
Excess water dilutes electrolytes in the blood and causes fluids to move inside cells, causing them to swell. When this happens to brain cells, it can be dangerous and even life-threatening.
"Biochemically, what's happening is a process of diffusion. So, the cells have a concentration of electrolytes, just like in the bloodstream. If one gets really out of whack, the body tries to balance it out, which could cause excess fluid to go into the cells," Gordon explains.
Sodium helps maintain the balance of fluids inside and outside of cells. When sodium levels drop due to excessive water consumption, fluids travel from outside to inside cells. Doctors call this condition "hyponatremia".
"It happens, but it is rare," Gordon says, noting that people should be aware to stay out of danger.
Similar to dehydration
Experts say excessive hydration symptoms are similar to dehydration, making it harder to catch.
One might have a headache, feel dizzy or light-headed, and suffer an episode of nausea — symptoms that are common to both conditions. This could be not very clear. The important question is, "Did I drink a lot of water? What colour is my urine? Am I thirsty?"
Clear urine is an indication you may have gone overboard. However, scientists say listening to your body will tell you how much water is too much.
"I don't think it's complicated because we have this sense of thirst. It allows us to balance our needs as far as hydration is concerned accurately and to make sure that we have the right concentration of electrolytes and volume in our bloodstream," says Gordon.
What's too much?
Experts reckon there is yet to be a definitive threshold for minimum or maximum water intake.
"No rigorous study says you should not exceed this, or you should have a minimum of that. If you think about it, children or babies need less water because of their size. If you are not active, you would use less, and if temperatures are cool, you would also use less," explains Gordon.
Based on approximation, even in reasonably extreme situations, an average person shouldn't drink more than a litre and a half of water per hour.
Adequate water intake also varies from person to person and is influenced by weather, physical activity and age.
"Also, take into account the fact that you do get about 80% of your water from beverages. Overall, you are probably okay with two to three litres a day," says Gordon.
People lose fluids through exercise, playing a sport, breastfeeding, and in hot weather, among others. "It is important to stay hydrated in heatwaves, but don't become paranoid in the opposite sense," Gordon warns.
He also cautions people against buying into the hydration craze, saying it could be harmful if unchecked.
"It's true that studies hint at improvements in cardiovascular conditions or urinary stones, for instance, because of hydration. So, there is a good reason to stay hydrated. But you find people gulping gallons of water, which isn't a solution. Like many things in life, there is a fine balance."
Attention thirst
Although data on deaths caused by water intoxication is hardly available, incidents have been reported in sports events and drinking competitions.
But WHO's focus has instead been on the persistent problem of poor water quality and sanitation, which kill nearly 1.4 million people yearly.
“For us at WHO, the real health issues around electrolyte balance are linked to dehydration from diarrhoeal diseases. That's where the real killers are," says Gordon.
As for water intoxication, awareness is the best antidote. When people experience symptoms of water intoxication, the standard response should be to stop drinking more water and immediately seek medical attention.
“You should see a doctor because there are things that they can do to make sure that the blood electrolyte levels are balanced. In more extreme cases, they can administer a saline with salts," advises Gordon.
It all comes down to balancing electrolytes in the bloodstream. This requires people to pay attention to their thirst, understand how much water they drank, and monitor the colour of their urine to ensure they do not slip into dangerous territory.
