Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Drinking water and your health

6-minute read

Drinking plenty of water every day is essential for good health. Australian tap water is the best choice for staying well hydrated.

Why is water important for good health?

Water is an essential part of a healthy balanced diet because the body relies on it to function properly. Between 50% and 80% of the human body is made up of water. All the body’s chemical processes take place in water. We need water for digestion, to absorb nutrients, to help us move, get rid of waste products and to regulate our body temperature.

If the body doesn’t have enough water (known as dehydration), it won’t function as well. People who don’t drink enough water every day are at greater risk of kidney stones, problems with their heart valves and some kinds of cancer. Even minor dehydration can affect physical and mental performance.

Drinking water is also essential for the health of your mouth. Drinking water in most parts of Australia contains fluoride, which helps to protect against tooth decay. Water is also needed for the body to make saliva, which is important for washing food away from the teeth and helping you chew, taste, swallow and digest food.

How much water should I drink?

The amount of water that someone should drink varies greatly from person to person. It depends on how your individual metabolism works, what the temperature is, what you eat, your age and whether you have a medical condition. It’s especially important for children and older people to drink enough water.

We get about one fifth of the water we need from food and the rest from drinking fluids. The body gets rid of water throughout the day through breathing and sweating, as well as by going to the toilet.

As a general rule, men need about 10 cups of fluids every day and women need about 8 cups (add another cup per day if you are pregnant or breastfeeding). Babies need 0.7 to 0.8 litres of fluid per day from breast milk or formula, while children need between 4 cups (for 1-year-olds) and 6 to 8 cups per day (for teenagers). In Australia, 1 cup is equivalent to 250ml.

You can get water from any fluids – including tea and coffee, fruit juice and soft drinks. But be careful how much of these you drink since they can make you put on weight, damage your teeth and have an unwanted stimulant effect.

Australian tap water is always the best choice – it’s free, tastes good and is usually safe. It’s a good idea to choose tap water over other drinks that contain added sugars or alcohol.

Is bottled water healthier than tap water?

Bottled water has no more health benefits than tap water. Tap water is just as safe to drink, unless there has been an incident in the area that affects the quality of the water, such as a flood or the discovery of bacteria in the supply. The fluoride in tap water is also important for healthy teeth.

Many people believe bottled water is healthier because it contains added minerals. However, studies have shown that bottled water can have less magnesium, potassium and calcium than tap water. Some varieties can also contain higher levels of potentially harmful substances, including chlorine, nitrate and chemicals released from the plastic such as bisphenol A (BPA).

Bottled water has lower quality controls than tap drinking water, while plastic bottles are not good for the environment.

Tips on how to stay hydrated

To stay hydrated, it’s important to drink before you feel thirsty. This is especially important if you are exercising or if it’s a hot day. Even if you’re not thirsty, try to drink water regularly throughout the day.

You can tell if you’re well hydrated by the colour of your urine. If it’s pale yellow or straw-coloured, then you are probably hydrated. If it’s darker, you need to drink more water. You can see the colour your urine should be on this NSW Health chart – but remember that taking some medicines or vitamin supplements can change the colour of your urine for a few hours.

You can stay hydrated by:

  • always carrying a water bottle with you
  • choosing water rather than tea, coffee or drinks that contain caffeine – these make you go to the toilet more regularly and so make you more dehydrated
  • keeping chilled water in the fridge on hot days
  • flavouring water with lemon, strawberries or mint to add flavour
  • always having water on the table when you’re eating

What happens when you don’t drink enough water?

Not drinking enough water can make you very ill. Severe dehydration can lead to dizziness and collapse. If you are showing any signs of dehydration, drink some water straight away and seek medical advice if you still don't feel better.

Older people are at greater risk of dehydration because they naturally feel less thirsty and their kidneys may not work as well.

Memory problems, taking some medicines such as diuretics and laxatives and not being able to move around to fetch a drink all make it harder to stay hydrated. For older people, not drinking enough water in the long term can lead to serious problems such as constipation, a decline in memory, not being able to function as well, having a fall, and having a stroke.

These are the signs that you need to drink more water:

Is it possible to drink too much water?

Drinking too much water can, in some people, lead to a dangerous condition called hyponatremia, where the levels of sodium in the blood become too diluted. This can occasionally happen to people who drink too much while they’re doing intense physical activity, such as running a marathon. Babies can also have too much water if their formula is too diluted.

People with chronic kidney disease, heart failure or liver disease, who can’t get rid of water from the body as efficiently, should talk to their doctor about how much water to drink. If you have some other long-term medical condition, it’s still a good idea to discuss your water consumption habits with the doctor.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: May 2019

Need more information?

These trusted information partners have more on this topic.

Top results

Water a vital nutrient - Better Health Channel

Water is essential for the human body to function.

Read more on Better Health Channel website

Drinking water - Water quality

A secure and safe supply of drinking water is fundamental to public health. The Australian Drinking Water Guidelines 2011 provide a solid foundation for assessing drinking water quality.

Read more on NSW Health website

Drinking water in Western Australia

About 90 per cent of Western Australians receive drinking water from licensed and regulated public drinking water supply systems (known as scheme suppliers).

Read more on WA Health website

Arsenic in drinking water | WA Health

Health risks associated with arsenic in drinking water.

Read more on WA Health website

Drinking water - myDr.com.au

The average person can survive for 40 days without food, but most people will die if they go for more than 72 hours without a drink.

Read more on myDr website

Fluoridated drinking water

Fluoride is found naturally in all water sources, including fresh and sea water. It is also found naturally in a wide range of food items including tea, fish and rice. It is a normal part of the diet, capable of providing nutritional benefits.

Read more on WA Health website

Emergency treatment of drinking water supplies

If disaster strikes, it is possible that the normal supply of water will be affected. When the safety of the water supply cannot be guaranteed, the Department of Health may issue advice to boil or treat it with chemicals prior to use.

Read more on WA Health website

Water quality :: SA Health

Safe Drinking Water Act 2011 and Safe Drinking Water Regulations 2012 - for providers of safe drinking water and guide for use of recycled water

Read more on SA Health website

Fluoride facts for Western Australia

In Western Australia 2 compounds containing fluoride are added to drinking water supplies

Read more on WA Health website

Environmental health | Australian Government Department of Health

The physical, chemical and biological environment we live in affects our wellbeing. Making sure we have clean drinking water, good hygiene, effective pest and disease control, and good housing is important to our overall health. Find out what were doing to improve environmental health in Australia.

Read more on Department of Health website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Government of Western Australia, health department logo