You may have heard that we need to drink 8 glasses of water (2 litres) per day. Whilst this is a good guideline, how much water we actually need per day varies from person to person.

Water makes up approximately 60% of your body weight. Your cells, organs, and tissues all utilise water in order to work properly. Some examples include using water to:

• Regulate body temperature
• Help rid the body of wastes (perspiration, urination & bowel movements)
• Keeps your joints well lubricated
• Protects your tissues

How to the tell if you’re not drinking enough water?

A good indicator to check whether your water intake is sufficient or not is looking at the colour of your urine. The clearer and paler it is then your good to go. The darker in hue, then its bottoms up!

What factors influence how much water you need?

Aside from your age, weight and size, other factors that can influence your water needs include:

• Exercise – Engaging in any physical activity that makes you sweat means you should be drinking extra water to replace the fluids you lost when perspiring.
• Pregnant – Pregnant women need to increase their fluid intake to support fetal circulation, higher blood volume and amniotic fluid (Montgomery 2002).
• Breast-feeding – When nursing, the hormone oxytocin is released signaling that you might be thirsty. Women should up their water intake when breastfeeding.
• General Health – If you are under the weather and suffering from illnesses such as fever, diarrhea or vomiting, you require more water to replace the fluid loss.
• Environment – Hot and humid weather can cause you to sweat and lose water, dehydration can also occur when at high altitudes which is why it’s important to up your water intake.

Is it possible to drink too much water?

It is possible, but unlikely. You can get ‘water intoxication’ or ‘hyponatremia’ which is its proper name, where the level of salt (sodium) in your blood becomes diluted and drops too low. This can be life threatening (Rondon et al. 2018). The salt in our blood is used by the body to balance fluids in and around your cells. If you drink too much water, this causes an imbalance, where the diluted excess water rushes into the cells and causes them to swell. As tissue such as muscle and fat are stretchy, your body can generally handle this to an extent, but cells in the brain cannot as our skulls do not stretch. Therefore, pressure can build up, and you may experience headaches, confusion and this can be fatal.

The good thing is, this is extremely rare. In healthy young adults this would only happen if you drank litres and litres all at once, because your kidneys can only process and expel approximately 800ml an hour.

The reason why doctors say infants under 6 months old should only drink milk or formula is because their bodies are that tiny that their kidneys haven’t matured enough to process lots of water.

However, remember as a population we are generally more on the dehydrated side than we are over-hydrated.

 

References:

Montgomery, K. (2002). ‘Nutrition Column An Update on Water Needs During Pregnancy and Beyond’, J. Print Educ. (3) pp40-42, NCBI [Online]. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1595116/ (Accessed 5 February 2019).

Rondon, H. Badireddy, M. (2018). ‘Hyponatremia’, StatPearls Publishing: University of Pittsburgh, NCBI [Online]. Available at: https://www.ncbi.nlm.nih.gov/books/NBK470386/   (Accessed: 9 February 2019).