Most of us are well aware that hydration is imperative to our health, brain function, and overall wellbeing. If you’ve scrolled through TikTok recently, you’ve probably even been tempted to invest in a Stanley tumbler or pastel-coloured two-litre water bottle as an incentive to drink more throughout the day.

If you have a tendency to forget to take a swig of water when life gets busy, then colourful and time-marked water bottles are helpful reminders.

Yet, there is also a danger of overhydration if you drink more fluid than your body can process. After all, that water you are glugging down has to go somewhere.

We’re well aware that there are some ’hydration myths’ swirling around, and we’ve even debunked some of the more pervasive ones. In 2022, a study found that drinking two litres or eight glasses of water a day (as widely recommended by everyone online) is in fact too much for most people.

In truth, the amount of water a person should consume depends on a variety of factors, including body weight, level of activity, environment and whether they’re pregnant or breastfeeding. 

Alongside this, research has found that our kidneys can only process 800ml to 1,000ml of fluid per hour. Therefore, if you drink more than that, then you’re out-drinking what your body has the capacity to process, which can have serious implications if it continues for hours on end.

On her neuroscience-based podcast, Do You F*cking Mind? Alexis Fernandez breaks down why the body can’t function properly with too much water.

“If you’re drinking more than 800-1,000ml per hour then you’re drinking more than can be processed and flushed out – and that water has to go somewhere. It can’t be processed through your kidneys so it ends up in your cells,” she explains.

As a result, your cells begin to absorb this additional water and it dilutes the amount of sodium concertation in our blood. Thankfully, our bodies are used to the odd cell expansion and designed to function completely normally with some water retention.

The only time this becomes dangerous is when a considerable amount of water (around 2 litres an hour) for several hours is consumed, as this leads to hyponatremia or water intoxication. However, for children or adults involved in high-intensity training, this limit will vary. 

It is common to see marathon runners or endurance athletes with hyponatremia as they drink a lot of water in an effort to quench their thirst, and the symptoms can be misinterpreted as dehydration. The signs of water intoxication are headaches, fatigue, confusion, nausea, vomiting and drowsiness.

In very rare cases, people have died from drinking an extreme amount of water (three to five litres) within a few hours, due to the pressure it places on their brain.

Fernandez continues: “Your tissue can swell up to some degree; your organs can swell to some degree, your muscles – all of that. But the problem is your brain cannot swell that much – it can only swell to what the skull will allow.”

In California, Jennifer Strange died of acute water intoxication after she drank 7.5 litres on a radio station’s water-drinking competition. The mother-of-three’s family was awarded over $16.5 million (£13m) in compensation after this tragic event, which she entered to win a Nintendo Wii for her children. 

This extreme case serves as a reminder that time-specific drinking contests (with any liquid) can be dangerous if they exceed what your body can safely process.

The NHS suggests that people should “aim to drink six to eight cups or glasses of fluid a day”, and notes that water, lower-fat milk and sugar-free drinks, including tea and coffee, all count. For reference, TikTok’s favourite Stanley dupe holds roughly 1,180ml of fluid. So there’s no need to chug down several of these a day, but one and a half is more than enough to keep you healthy.

If you’re already a regular water drinker then it might be time to ease up if you’re at risk of over-saturating your body with fluid.

If you still feel thirsty even after drinking sufficient water, please get in touch with your GP to find out what’s causing your excessive thirst.

Images: Getty