Benefits Of Drinking Water

What is water

Water is a naturally occurring compound which consists of two elements: hydrogen and oxygen. This gives water the chemical formula H20. Water is also tasteless, odourless, and almost colourless.1 It is the main component of the earth, making up 71% of the earth's surface. It is also the main component of living organisms, with 60% of the human body being water. It is vital for all life as it helps to:

  • Regulate body temperature 
  • Protect organs and tissue
  • Carry nutrients and oxygen to cells
  • Lubricate joints
  • Dissolve nutrients and minerals.

In most economically developed countries, water is safe to drink out of the tap. The taste and smell can differ slightly due to the treatment of that water. For example, water in the UK is chlorinated to kill harmful bacteria in the water. 

Depending on where you live the pH of water can vary. pH is a value given to something to determine how acidic or alkaline something is. For example, stomach acid has a pH of 1.5 to 3.5 (strongly acidic), and bleach has a pH of 11 (strongly alkaline). The pH of water can vary depending on how pure it is, which is determined by the source and the treatment. 

The source of the water can determine the mineral content which changes the pH. If you live in an area like the southeast of England, your water could be pH 8.5+ due to the large amount of calcium in the water. This is known as hard water. It is safe to drink but can cause buildups of limescale on your pipes, taps, and kettles. If you live in parts of Scotland, the water is much softer due to the nature of the rocks the water naturally flows through. Any water that naturally contains minerals is referred to as mineral water.

The EPA recommends drinking water in the range of pH 6.5 to 8.5. On the backs of bottled water, you can see the content of minerals and pH value.2

What are the benefits of drinking water

There are numerous benefits to drinking water.

  • Assists in optimising physical performance. Staying hydrated is particularly important during intense exercise. Dehydration can have a noticeable effect even if you lose as little as 2% of your water content. This is because muscles are 80% water. Dehydration can lead to reduced motivation and increased fatigue, making it more difficult to exercise. Adequate hydration has been shown to prevent this from happening and can even reduce the physical stress that occurs during intense exercise.3,4 
  • Energy levels and brain function. Studies show that dehydration of between 1-3% of your body weight can impair brain function. Two studies were conducted by the same team: one on people assigned female at birth and one on people assigned male at birth. The studies found that fluid loss of 1.4% in women and 1.6% in men after exercise impaired mood, working memory, and increased fatigue.5,6
  • May help prevent and treat headaches. Headaches are one of the most common symptoms of dehydration. One study showed that drinking 1.5 litres more water per day resulted in improvements in a scoring system to assess migraines. However, not all studies support this theory and so more evidence is required. This is probably due to the fact that several things can cause headaches and migraines.7
  • May relieve constipation. Mineral water may be particularly beneficial due to minerals such as sodium and magnesium which increase bowel movement frequency.8
  • Managing postural hypotension. Postural hypotension is a condition where your blood pressure drops dramatically when standing up making people feel faint and dizzy. Drinking 300 to 500 ml of water can remedy this. Water’s immediate effect on the body reduces heart rate and increases blood pressure which is thought to occur due to increased blood volume.9
  • Aid weight loss. Water can increase the feeling of being full which may reduce the amount of food you eat. Timing is particularly important. One study showed drinking 0.5 litres of water 30 minutes before eating proved to be the most effective.10
  • Help prevent hangovers. Alcohol has a diuretic effect on the body which means that your body increases the amount of urine you produce which can cause dehydration. Although dehydration is not the main cause of hangovers, staying hydrated can reduce some of the symptoms of dehydration.11

How much water is enough

There is no definitive answer to exactly how much water is enough. The amount of water you need will vary greatly due to the climate you live in, your activity level, and your overall health. Many people recommend having around 2-3 litres of water per day. This includes tea, coffee, milk, and all other beverages. 

You will require more water if you live in a hotter country, as you lose a lot of water through sweating. You will also require more water the more you exercise as you will sweat more losing water. 

If you have health problems related to your kidneys, then you will need to modify the amount of water you drink, as your kidneys can not eliminate the same amount as an otherwise healthy person's. Most people will not need to drink more than 3 litres of water per day. However, drinking too much water can be as bad as not drinking enough. 

Instead of looking for a particular number of litres to drink, look at the colour of your urine. Urine should be a pale straw colour. If it is lighter than this, you may be drinking too much water and if it is darker, not enough.9

Things to notice when you are dehydrated

Dehydration is usually caused by severe vomiting or diarrhoea, but can also be caused by not drinking enough, sweating too much, urinating too much, or certain medication and alcohol.12 The signs and symptoms of dehydration are:

  • Dark coloured urine
  • Feeling thirsty
  • Dizziness or light-headedness
  • Feeling tired
  • Dry mouth
  • Urinating fewer than 4 times a day

Tips to help you drink more Water

Making sure you drink enough water does not have to be stressful and here we have provided a few tips to help you:

  • Investing in a reusable bottle
  • Incorporate more food with high water content i.e., fruit and veg 
  • Drinking during exercise


Water is a vital component in our lives, and being adequately hydrated helps us to function optimally. As a rule, 2 - 3 litres should be adequate for most people. However, this is not a concrete number, and some people may require more or less depending on the factors discussed.


  1. PubChem. Water [Internet]. [cited 2022 Nov 10]. Available from:
  2. US EPA O. Drinking water regulations and contaminants [Internet]. 2015 [cited 2022 Nov 10]. Available from:
  3. Ayotte D, Corcoran MP. Individualized hydration plans improve performance outcomes for collegiate athletes engaging in in-season training. J Int Soc Sports Nutr [Internet]. 2018 Jun 4 [cited 2022 Nov 10];15:27. Available from:
  4. Paik IY, Jeong MH, Jin HE, Kim YI, Suh AR, Cho SY, et al. Fluid replacement following dehydration reduces oxidative stress during recovery. Biochem Biophys Res Commun. 2009 May 22;383(1):103–7. 
  5. [cited 2022 Nov 10]. Available from:
  6. Ganio MS, Armstrong LE, Casa DJ, McDermott BP, Lee EC, Yamamoto LM, et al. Mild dehydration impairs cognitive performance and mood of men. British Journal of Nutrition [Internet]. 2011 Nov [cited 2022 Nov 10];106(10):1535–43. Available from:
  7. [cited 2022 Nov 10]. Available from:
  8. Bothe G, Coh A, Auinger A. Efficacy and safety of a natural mineral water rich in magnesium and sulphate for bowel function: a double-blind, randomized, placebo-controlled study. Eur J Nutr [Internet]. 2017 [cited 2022 Nov 10];56(2):491–9. Available from:
  9. Popkin BM, D’Anci KE, Rosenberg IH. Water, hydration and health. Nutr Rev [Internet]. 2010 Aug [cited 2022 Nov 10];68(8):439–58. Available from:
  10. Dennis EA, Dengo AL, Comber DL, Flack KD, Savla J, Davy KP, et al. Water consumption increases weight loss during a hypocaloric diet intervention in middle-aged and older adults. Obesity (Silver Spring). 2010 Feb;18(2):300–7. 
  11. Polhuis KCMM, Wijnen AHC, Sierksma A, Calame W, Tieland M. The diuretic action of weak and strong alcoholic beverages in elderly men: a randomized diet-controlled crossover trial. Nutrients [Internet]. 2017 Jun 28 [cited 2022 Nov 10];9(7):660. Available from:
  12. Dehydration [Internet]. 2017 [cited 2022 Nov 10]. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Rob Reid

Master of Pharmacy - MPharm, Medway School of Pharmacy

Robert is a highly creative and technical individual with a strong scientific background and experience in both hospital and community pharmacy currently interning as a medical writer at Klarity.

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