We all know the importance of drinking water being a good thing for our health. But are you wondering whether drinking too much is a bad idea or how much should one drink a day?
What are the side effects or symptoms that can be triggered from drinking too much or too little water?
Here are some documented researches from medical literature, all references at the end of this article.
Happy reading!
Any questions? remarks? Let’s meet in the comments section at the end of this article.
Last updated: Jan 2025. Written by Juliet Semakula, a diagnostic radiographer.
Disclaimer: no affiliate links.
Why is it good to drink water every day?
Water is important to our body in so many ways for example.
Water helps regulate our body temperature.
It helps prevent constipation
Helps flush out any waste products in our body.
And help perform all major bodily functions.
According to Meinders 2010: research
An adult man of 70kg consists of approximately 42 litres of water of which 28 litres are intracellular and 14 litres extracellular.
This water sits in different body parts such as cerebrospinal fluid, eye, pleura, peritoneum, synovia and interstitial. A shortage of water can risk these cellular and extracellular functions.
Water acts as a solvent, substance, metabolic product building material that acts as a medium in which transport systems work in our body.
Reminder: How much water do we really need to drink
I have always asked this question on so many occasions, how much water is ok to drink a day.
And I believe in your spaces in sports, lecture halls and classes you have seen people with a bottle of water from which they occasionally take a sip.
You are familiar with the formula: An adult should drink between 1.5 and 2 litres of water a day.
According to Meinders 2010: and other researchers.
The water balance in our body varies by no more than 0.2% of the body weight per 24 hours.
And we lose about 500ml of water via our skin,300 ml via breathing and 150 ml via faeces and urine.
Water intake in food
And the water absorbed through food is approximately 700ml depending on the type and amount of food.
And about 300ml of water is released during metabolism depending on the energy consumption and type of substrate.
The balance consists of the amount we drink which is usually average, and your needs may vary depending on different factors.
Meinders ,2010
For a healthy adult under normal circumstances, you should be able to drink about 500ml or half a litre a day which is necessary for the body organs to function.
If there is additional loss of water, the water intake must of course be increased accordingly.
How much you drink a day will depend on your needs which may vary depending on different factors.
♦Your weight
♦Your age
♦If you are pregnant
♦The climate in which you live
♦Your level of physical activities
♦If you sweat more than average.
♦If you are sick or recovering from illness.
Other recommendations from other sources:
I predict you may have had 8×8 ounces of water a day, coming from the USA. This means 1900 ml of water per day which seems over exaggerated in addition to all the other fluids in food we have discussed above.
You must also have had a common advice of drinking 2 litres versus 1 litre of water a day on overall health.
However, all these findings about how much we should drink a day are not backed by scientific findings nor do the UK or Eu official guidelines say we should drink this much.
It is up to you to make a judgment on how much water you can drink a day.
If you can at least drink 500 ml or more a day it will help keep the water balance in the body and reduce dehydration. This is better than not drinking at all.
Summary: there are no convincing arguments for how much you should drink a day, but the choice as a healthy adult should be in your hands.
For an adult meal you should at list drink 2 litres or less a day and female 1-1.5 or 2.2 litres or less a day.
According to Nakamura,2020
At present, it is not clear whether the health benefits of drinking water are due to changing habitual water intake, even though it may also have an impact on indicators such as blood pressure or kidney function.
How can you tell if you are drinking too much water? What are the symptoms of being over hydrated?
One of the doctors I spoke to about how I can identify symptoms or risks of drinking too much water, had this to say:
It’s always a challenge to diagnose or identify some symptoms because they are not very specific, as they also appear in other contexts.
When you drink too much water over a short period of time, we mean drinking 1 litre of water every 30 minutes. This can be probably too much.
Here are some of the symptoms you might notice.
Your urine in normal terms is light yellow but when it shows a very clear or colourless colour this may be an indication you are drinking too much water.
If you start feeling nauseous, bloated and vomiting
Headaches
Confusion and disorientation
What are the known risks associated with excessive water consumption?
It’s been noted that drinking too much water can be more dangerous when exercising.
Drinking too much water can cause water toxicity, an electrolyte imbalance to your body especially during physical exertion.
Caution:
this can make it worse when you have other medical condition that can also make your body retain too much water, regardless of how much you drink.
When you drink too much water during exercise you may face a risk of hyponatremia which means ‘not enough sodium in the blood’
Here water dilutes the sodium in your body, remember sodium is essential for fluid balance in the body and when it’s low, it can cause serious symptoms such as.
Nausea.
Headache.
Unconsciousness which may lead to a coma, this is rare but when it happens it can be fatal.
Source: Hoffman 2016
Others rare risks can be:
When you crave water excessively due to a persistent sensation of thirst which in medical terms is called psychogenic polydipsia.
During water competitions or water ingestion in prison torture.
Kidney disease or endocrine problems.
Certain medications such as antidepressants.
Gastroenteritis causing water loss.
Peechakara, 2023
How do you find the right balance in your water consumption?
Finding the right balance on how much you can drink a day will depend on how you see the importance of drinking water.
You should not force yourself to drink to compensate for any small loss of water.
You can simply drink as you feel thirsty. This will limit any risks associated with water consumption of drinking too much or too little.
Some people do drink when they feel thirsty, which is not bad. This helps with any dehydration especially after physical activities when you think you have lost a lot of water.
Typically, the volume of water drunk in response to thirst matches the deficit you may have lost during physical exercise (Saker, 2016)
So, if you are very thirsty, drinking 2 to 3 litres of water a day is not a problem.
What happens if I drink too little a day: Disadvantages.
Nothing will happen at that moment if you drink too little a day or nothing at all.
But this may lead to the following consequences in the following days or weeks if you continue going without water :
You will not be able to produce enough urine for the required excretion of osmoles.
Avoid disturbing the sensation of thirst especially when you are old, on medication or have any illness because it can lead to dehydration.
You may have constipation.
You may feel dizzy or lightheaded.
Remember water helps support brain function and other body organs. So, it is important that you try to drink at least 1 or 2 glasses of water.
Or you can mix your water with fruit juice that can give you some flavour if you think plain water is hard to drink.
We have come to the end of this article, I hope I have answered some of your questions.
Let’s keep our bodies healthy by drinking water.
Sources.
Meinders AJ, Meinders AE. Hoeveel water moeten we eigenlijk drinken? [How much water do we really need to drink?]. Ned Tijdschr Geneeskd. 2010;154:A1757. Dutch. PMID: 20356431.
Hoffman MD, Bross TL 3rd, Hamilton RT. Are we being drowned by overhydration advice on the Internet? Phys Sportsmed. 2016 Nov;44(4):343-348. doi: 10.1080/00913847.2016.1222853. Epub 2016 Aug 22. PMID: 27548748.
Nakamura Y, Watanabe H, Tanaka A, Yasui M, Nishihira J, Murayama N. Effect of Increased Daily Water Intake and Hydration on Health in Japanese Adults. Nutrients. 2020 Apr 23;12(4):1191. doi: 10.3390/nu12041191. PMID: 32340375; PMCID: PMC7231288.
Saker P, Farrell MJ, Egan GF, McKinley MJ, Denton DA. Overdrinking, swallowing inhibition, and regional brain responses prior to swallowing. Proc Natl Acad Sci U S A. 2016 Oct 25;113(43):12274-12279. doi: 10.1073/pnas.1613929113. Epub 2016 Oct 10. PMID: 27791015; PMCID: PMC5086996.
Peechakara BV, Gupta M. Water Toxicity. [Updated 2023 Jun 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537231/