How much water is too much water?
While we’re always told to drink plenty of water in order to stay hydrated and healthy, there is a limit to this – although the limit of what verges on unhealthy or dangerous is not very easy to identify.
“Too much of anything can be a bad thing,” says Dr Ciara Yeates, General Practitioner at the private GP clinic London Doctors Clinic. “Generally, the recommendation for a healthy adult is to consume 2-2.5 litres of water per day. However, this will vary depending on things like your height, weight, sex and activity levels. This total also includes water you may get from your diet, particularly if you eat things that have a high water content, such as soups, salads or fruits.”
According to Medical News Today, your kidneys can eliminate about 20-28 litres of water a day, but they can't get rid of more than 0.8-1.0 litres per hour, so to avoid overhydration, you shouldn’t drink more than this each hour. And if you do drink too much, look out for the symptoms featured below.
Too Much Water Can Make Your Body Swell
If your water overconsumption is particularly severe, one of the first things you’ll notice is swelling in the hands, lips or feet. According to the MSD Manual, this is a tell-tale sign you’re experiencing an electrolyte imbalance – drinking too much water can lead to low sodium levels in the blood, causing the body’s cells to retain fluid and swell.
Our kidneys are what control the amount of water, salt and waste leave the body by filtering out of your blood and making urine. But when someone drinks too much water in a short period of time, the kidneys can’t flush it out fast enough, and your blood becomes waterlogged. This water will eventually try to leave the blood and enter cells where the concentration of salt is highest, causing the body to swell. The best way to reduce this swelling might seem obvious – simply to reduce your fluid intake – it still must be done under the advice and supervision of a doctor.
You’ll Get Shaky, Weak Muscles
For those who like to exercise, drinking water is an absolute necessity. But it’s important not to go too overboard on the rehydration, otherwise those shaky legs and muscle spasms might not be the result of going hard on leg day. According to the Mayo Clinic, this again comes down to low sodium levels in the blood – so if you feel shaky or your muscles are painful and it doesn’t seem to be related to exercise or any physical strain, it could be that you’re lacking those key electrolytes.
You Can Suffer From Splitting Headaches
Low sodium concentration in your blood will not only cause your body to swell, but can also have the same effect on brain cells. This expansion leads to pressure on the skull– so a painful headache might mean you’re experiencing swelling from overhydration.
It Can Lead To Seizures
Occasionally – but, Dr Yeates notes, quite rarely – these low sodium levels from overhydration can lead to a dangerous condition called hyponatremia: “It happens if you are losing fluids, but also sodium, and can lead to fits. We see this in people who take part in endurance events or very strenuous exercise, and also when people are unwell with diarrhoeal illnesses.” A 2014 study shows that this kind of swelling on the brain from water can also lead to brain damage and comas.
Dr Yeates also advises that if you are training for an athletic event, it’s wise to seek medical advice on adequate hydration. “Similarly, if you are unwell, unable to drink as much as normal or are suffering from diarrhoea or vomiting, you should seek advice from a health professional.”
You Can Die From Drinking Too Much Water
Although unusual and extremely rare, water intoxication is a real thing, and there are several cases of people dying from drinking too much water. In 2007, a 28-year-old woman died after competing in a radio station’s water drinking competition called ‘Hold Your Wee for a Wii’. After sinking six litres of water in just three hours, Jennifer Strange vomited and went home with a bad headache – where she later died from water intoxication. Patients with abnormally low salt levels, as a result of hyponatremia or water intoxication, have a death rate of almost 30 per cent.
As Dr Yeates says, it’s important to seek medical advice on how much water is too much water, but Dr Imran Rafi, chairman of clinical innovation and research at the Royal College of GPs, notes that while it’s important to stay hydrated, there’s no definite recommendation as to how much people should drink: “There is no steadfast recommendation as to how much water people should drink in order to stay healthy, but the key thing is to keep hydrated – and passing clear urine is a good indication of this. Excessive water intake can have important consequences for patients, and this is something that healthcare professionals, and patients, should be mindful of.”