Drinking too much water when ill can be harmful, finds study

Apart from cavilling at the wording (surely it is almost the definition of "too much" that it can be harmful!), this article highlights something that is so very important. Lots and lots of water is not good for us.

For a change, it is the "medicial advice" that is criticised rather than patients. So who was responsible for the poorly worded advice that sends the wrong message. We should be told!!!

Drinking too much water when ill can be harmful, finds study

Doctors warn excessive intake can pose risks for some patients and say medical advice needs to be more specific

The common advice to drink plenty of water when ill is based on scant evidence and can actively harm chances of recovery, doctors have warned.

Medics at King’s College hospital NHS foundation trust, in London, raised the alarm after they treated a patient with hyponatremia – abnormally low sodium – from drinking too much water to help with a recurring urinary tract infection.

In the case highlighted, a 59-year-old woman consumed several litres of water based on medical advice she recalled from previous similar episodes to “flush out her system”. She became progressively shaky, muddled, vomited several times and had significant speech difficulties.

Rest of article available here:


I usually quote the very sad story of the woman who suffered severe brain damage after following advice to drinks large quantities.

Also, well worth pointing out, the amount is meant to include coffee, tea, soft drinks, even soup!

25 Replies

  • I'm afraid I'm going to be unsympathetic to the person who drank too much water. If I get medical advice to drink plenty of water I would just try and drink the same amount as I usually do or just a little bit more. I wouldn't decide that meant I had to drink several litres.

    My husband annoys me when he gets a bad cold or flu. He seems to lose almost all desire to drink, and just sips tiny amounts when I tell him he needs to drink more fluids, and I think the advice to drink plenty should be aimed at people like him. The result of this lack of drinking is that his temperature always rises very high indeed and he is ill for twice as long as me, if I get the same thing. I realise my temperature might be lower than his because I'm hypothyroid. But the length of time he is ill is nothing to do with hypothyroidism, I'm sure.

  • Some people do lose the desire to drink when they are ill or feeling cold. I do.

    The only thing you can do in your husband's case is see what he does actually drink and give him more of it. Being annoyed with him won't make him drink more.

    In my case I only drink more when I see the colour of my urine, but it does help knowing someone who ended up in hospital when they were 20 because they didn't drink enough.

  • I agree that being annoyed won't achieve anything. But I've known my husband for about 35 years and having the same good advice ignored over and over again for that length of time would try the patience of a saint. And I'm definitely not a saint. ;)

  • Man flu? ;-)

  • To be fair to my husband, he isn't very demanding when he is ill. He's just annoying because he won't do what he knows is in his best interests. He's got away with this so far, but he's getting to an age where his body is bound to be less resilient to the effects of severe colds and flu, and I worry that lack of fluids during illness might damage his kidneys or other organs, particularly since his temperature gets so high.


  • Have you tried threatening to spray cold water on him to lower his temperature, unless he drinks more? :D

  • Wow! Err...no, I haven't tried that. I'll try and remember it for next time. :D

  • When I was 'ill' - presumed kidney failure, which turned out to be a side effect of one of the medications they were forcing into me to 'treat' my presumed arrhythmia - my doctor told me to drink 3 litres as day!

    I didn't, of course. I'm not that daft. lol

  • I don't know anything about kidneys. Surely there must be a happy medium between drinking enough to keep the kidneys "clean" and not drinking so much that the kidneys get over-taxed? Or am I just talking out of my hat?

  • I don't either. Nor do l think my doctor knew. He didn't even know that kidney failure was one of the symptoms of that particular drug and rushed me off to hospital - where an arrogant junior doctor, who thought he was God's gift to medicine, got his first lesson in doctor/patient relationships, and diplomacy, when he very haughtily told me l should drink water at home. (He didn't say what l should drink elsewhere.) Notice, he didn't say more water, just drink water. He left the room with the certitude that l did, indeed, drink water at home. And everywhere else, come to that! lol

  • would love to have been a fly on the wall gg :))

  • You'd have been swatted...

  • Funnily enough sports scientists have been researching the right amount to drink for years. They recommend drink when thirsty.

    This is because in endurance events e.g. marathons people have died from drinking too much, and they have issues with the sports drinks industry particularly it's nonsense advertising over hydration. (Yes people who do sports are normally healthy people but not everyone is as you get those undergoing cancer treatment running.)

    So I'm not surprised that doctors have finally been caught out for talking rubbish. it's even sadder when the research was there already.

  • How many of us on here are too painfully aware that doctors talk a whole lot of rubbish!!! :-/

  • I have drunk water everyday since I was a small child. I remember everyone trying to get me to drink tea, coffee, etc. Now 70 years later I am still on my water. I drink about 1+ liters per day.

    The answer to most questions is moderation, food, water, exercise, work, shopping. etc.etc

  • Many, many years ago I had gone for lunch with a couple of colleagues to a rather nice canal-side pub. This was unusual for the time in being run by a chef rather than a more traditional publican. Their food was excellent and relatively affordable.

    As usual, we ordered drinks (probably a pint each) and food, found a table and sat drinking and waiting. An elderly gentleman started saying something. By the time I joined in he had been acting a bit like the Ancient Mariner in giving us a warning. Don’t drink at the same time as eating. Drink before. Drink after. But not actually with food. For some reason doing so would make us ill. On asking a bit more, it seemed he meant maybe a quarter or a half hour gap either side, so not difficult to achieve most of the time. It didn't matter whether it was water, tea or beer.

    From time to time, I recall that conversation. Does drinking (more than a sip or two) with food reduce our capacity to digest by diluting the enzymes and acid? Or is there some other basis for the warning?

  • Helvella,

    I think drinking large amounts (say, pints) whilst eating can interfere with the natural//necessary levels of bile//stomach acid//enzymes so hindering digestion.

    I have previously read that drinking water half an hour before and after is more beneficial than drinking with food but I always have half a pint of water//herbal tea with my meals. Adding cider vinegar or lemon juice for those with low stomach acid would help digestion any way.

  • I was told a very long time ago to drink a glass of water half an hour before eating so that the body is hydrated enough to function, & the stomach won't get overbloated by eating & drinking at the same time.

    I still stick to this, unless I'm eating socially, & tend to drink a lot between meals that also contain a lot of fluid.

    My fluid intake must be well in excess of 3 litres a day, & has been for as long as I can remember, if I include foods as well as liquid. I am constantly thirsty, & feel hungover if I am dehydrated. Oddly, since drinking a huge coffee every day, I've noticed less thirst. I supposedly don't have diabetes insipudus, but wonder if that's the same as the secondary hypothyroidism that I also supposedly don't have?


  • I'm a person who drinks a lot, and I found the article frustratingly vague, as I do always wonder what constitutes too much. I tend to drink about 3-4 liters, and have had similar advice to GG from haematologists, that I should drink 3 litres plus. My understanding is that those who over drink during marathons and dancing on drugs are having much more. But the article doesn't suggest a figure for what might be too much.

    3 litres is named as an example of a 'normal' intake, and 1 litre is the amount the woman was kept to in hospital in order to reduce her levels, which suggests it's a very low quantity?

    But at the same time, dehydration is mentioned as a general , danger for all, while over drinking is limited to just two specific people, and those in extreme circumstances, so the message is a bit muddled.

  • It could also be questioned whether the wholesale advice to consume less sodium chloride (common salt) is appropriate in those who do drink a lot. After all, it was hyponatremia (low sodium) that was the identified issue.

  • Yes, that did cross my mind. Maybe I should have a sprinkling of salt in a few of my glasses, and then the quantity isn't as important.

  • Nope.

    Sports science research indicates you don't have to.*

    I've got two relations who gave been told by haemotolgists with different probkems who have been told to drink 3-4litres a day. So I suspect that haemotolgists tell most patients they see to drink that much regardless of what the condition is.

    *You can google for the info as I'm writing on a phone.

  • How much is too much?

  • If you aren't thirsty and drinking a lot then that's too much.

    The problem is the amount you need to drink depends on temperature, other environmental factors like air conditioning, what you are doing, health, genetics and body size.

    So if it's 30 Celsius and you have done a 20 minute walk you will very likely need to drink afterwards, but if it's 8 Celsius and you do the walk you probably won't need to.

  • I remember in the mid 70's this came to light. It was discovered back then that too much water can "flush out your electrolytes". This made an impression on me and I was cognisant of how much liquid I drank. Then I moved to North America - and everyone was carrying around a bottle of water! (They still are). So take heed American readers, this nugget of info may not have reached your (our) shores yet.

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