How much fluid should I drink to help keep my kidneys healthy?
The human body can last weeks without food, but only days without fluid. It has no way to store the fluid it needs to replenish the blood, in order for body functions to work properly, to make up for losses from lungs, skin, urine and faeces.
Fluid regulates your body’s temperature through perspiration, the kidney removes waste via urine and carries nutrients and other substances throughout the body.
So what should you drink?
Fresh supplies of fluid are needed every day, however, there is no set amount to drink each day to avoid dehydration.
Water is the recommended fluid to satisfy thirst and is nature's choice. It is calorie-free, inexpensive and readily available and choosing to drink water instead will have a positive impact on your health. It can also contain fluoride which is good for teeth.
Swap sugar loaded drinks for water as it is so much better for your health - be sugar free!
Note: bottled mineral water contains salt which can lead to fluid retention, swelling and even increased blood pressure in susceptible people. Check the label and choose low sodium varieties (less than 30mg sodium per 100ml).
KIDNEY HEALTH AUSTRALIA - POSITION STATEMENT ON DRINKING WATER
Dr Timothy Mathew Medical Director - Kidney Health Australia (Last reviewed June 2008)
The desirable amount of water to drink each day has been promoted to the public in recent years to be 8 glasses each of 8oz (= 240 ml) each 24-hour period.
This view had in the past been publicised by water authorities and bottled water manufacturers, with endorsement of this view by Kidney Health Australia.
However, after our Kidney Health Australia medical team conducted a critical review of the published literature on this topic, we found there is a distinct lack of evidence supporting this position.
As a result of this review in 2003, our Board of Directors adopted the following position in regard to water intake:
There is a lack of evidence that drinking water in excess of thirst is beneficial for the health of Australians living in temperate regions and not exercising strenuously.
The daily fluid intake needs are increased in:
all residents in tropical or hot climates
individuals practising strenuous exercise
certain medical conditions characterised by excess obligatory fluid loss
certain medical conditions requiring an increased urine flow
The daily fluid intake needs are decreased in most patients with:
From the kidney viewpoint, all fluids including those containing
caffeine and alcohol should count towards your daily fluid total.
Kidney Health Australia's Position Statement on water fluoridation
National Kidney Foundation (USA) updated Fluoride Position Statement for people with CKD April 2008
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OTHER SOURCES OF FLUID WHICH HYDRATE THE BODY
You don't need to rely only on what you drink to satisfy your fluid needs
What you eat also provides a significant portion of your fluid needs. On average food provides about 20 percent of total water intake, while the remaining 80 percent comes from water and beverages of all kinds.
Many fruits and vegetables, such as watermelon and cucumbers, are nearly 100 percent water by weight. Beverages such as milk and juice are also made up of mostly water. Milk is important (especially for children) and tea can be a source of antioxidants which appear to protect against heart disease and cancer.
Fresh fruit is preferable to fruit juice as it offers more fibre and nutrients and much less sugar. Even beer, wine and caffeinated beverages such as coffee, tea or soft drink can contribute, but should not be a major portion of your daily total fluid intake.
Sweet drinks should be limited as they add calories without nutrient value. Caffeine or alcohol may cause or worsen health related problems and should be avoided except in modest quantities. You may wish to consider these tips to satisfy your thirst:
- keep a jug of water in the fridge
- ask for a bottle of water for your table when dining out
- drink one for one - a glass of water to an alcoholic drink
- add lemon, lime or orange to add zest to your water
- try substituting a second cup of coffee or tea, with a glass of water
- take a bottle of water with you wherever you go, especially when traveling
- suck on ice-cubes in hot weather
SITUATIONS WHEN YOU NEED TO LISTEN TO YOUR THIRST!
Though no single formula fits everyone, knowing more about your body's need for fluids will help you estimate how much water to drink each day. The amount of fluid you need to drink depends on your size, activity level and the weather. The best way of knowing how much to drink is to drink enough to satisfy your thirst. Refer to our Fact Sheet: How to look after your kidneys
If you have severe kidney disease
Your healthcare team will let you know if you need to limit fluids and how much fluid you can have each day. See * Nutrition and CKD * Chronic Kidney Disease * Urinary Health.
The more you exercise, the more fluid you'll need to keep your body hydrated. During long bouts of intense exercise it is best to use a sports drink that contains sodium, as this will help replace sodium lost in sweat and reduce the chances of developing hyponatremia, which can be life-threatening. Fluid levels should be topped up to replace sweat produced through exercise.
Hot or humid weather can make you sweat and requires additional intake of fluid. Heated indoor air also can cause your skin to lose moisture during wintertime. Further, altitudes greater than 2,500 meters (8,200 feet) may trigger increased urination and more rapid breathing, which use up more of your fluid reserves. An air traveler can lose approximately 1.5 litres of water during a three-hour flight.
For teachers and kids
Enjoy singing about the importance of 'drinking water instead' to be 'sugar free', to help your kidneys stay stronger longer! A very cool song and excellent education tool which is FUN!
Kidney Health Australia have participated in several Kidney Health Festivals in communities in the Northern Territory. Listen to songs created by the communities. This well produced song by the Tiwi kids on Bathurst Island -Tiwi Islands, a very hot environment, sees Billy da Kid-Kidney leading the group who want to be sugar free, so they drink water instead!
Illnesses or health conditions
Signs of illnesses, such as fever, vomiting and diarrhoea cause your body to lose additional fluids and in these cases - you should ensure that you keep your body hydrated! Certain conditions including bladder Infections and urinary tract or kidney stones, also require increased water intake. On the other hand, certain conditions such as heart failure and some types of kidney, liver and adrenal diseases may impair excretion of water and even require that you limit your fluid intake.
Pregnancy or breast-feeding
Women who are expecting or breast-feeding need additional fluids to stay hydrated. Large amounts of fluid are lost especially when nursing.
You may need more fluid in your diet if you are:
- on a high protein diet
- on a high fibre diet, as fluids help prevent constipation
- have an illness that causes vomiting or diarrhoea
- are physically active or exposed to warm or hot conditions
Important facts about our internal fluid supply
- fluid loss needs to be replaced
- body fluid is higher in men than in women and falls in both with age
- fluid loss may be more in hot weather and with prolonged exercise.
- most mature adults lose about 2.5 to 3 litres of fluid per day
- elderly people lose about 2 litres per day
- an air traveler can lose approximately 1.5 litres of water during a three-hour flight
WHAT IS DEHYDRATION?
Dehydration occurs when the water content of the body is too low
It can be easily fixed by increasing your fluid intake. It is very important that you listen to your body's signals that you are thirsty or have not had enough fluid intake. Symptoms of dehydration include headaches, lethargy, mood changes and slow responses, dry nasal passages, dry or cracked lips, dark coloured urine, weakness, tiredness, confusion and hallucinations.
If you do not have enough fluids to keep your body hydrated, eventually urination stops and your kidneys will fail. The body can’t remove toxic waste products and in extreme cases, this may result in death.
Causes of dehydration include:
- increased sweating due to hot weather, humidity, exercise, or fever
- increased output of urine due to a hormone deficiency, diabetes, kidney disease, or some medications.
- diarrhoea or vomiting
- recovering from burns
Dehydration - symptoms and what to do:
Early dehydration - dry mouth, thirst, restless or irritable behaviour, headache, mild muscle cramping.
Moderate dehydration - dry mouth, extreme thirst, flushed face, headache, warm and dry skin, lack of urine production, dizziness, weakness, cramps in the arms and legs.
Severe dehydration - all above, plus severe cramping, low blood pressure, fainting, convulsions, bloated stomach, lack of elasticity of skin, rapid deep breathing, fast and weak pulse – in extreme cases, heart failure.
Treatment - If you develop early signs of dehydration, get out of the sun; ideally go somewhere cool, in the shade. Splash yourself with tepid water or apply cool, wet cloths to your face and neck and drink water slowly, small sips at a time. If your symptoms are not relieved within half an hour or so, or you go on to develop severe symptoms such as an inability to pass urine, vomiting, weakness or cramping, consult a doctor immediately.
Dehydration in elderly
Insufficient signalling mechanisms in the elderly mean that they do not feel thirsty, even though they may be dehydrated. Keep this in mind if you are caring for an elderly person as they may need prompting around fluid intake.
Some negative effects of dehydration in the elderly may include mental confusion, dry skin, migraines, hypertension, digestive complications and persistent constipation. Severe dehydration over time could even cause organ failure. Elderly people are often at risk of dehydration due to:
- changes to kidney function, which declines with age
- hormonal changes
- not feeling thirsty
- medication (for example, diuretics and laxatives)
- chronic illness
- limited mobility
Dehydration in children
Children are susceptible to dehydration, particularly if they are ill. Vomiting, fever and diarrhoea can quickly dehydrate a baby. This can be a life-threatening condition. If you suspect dehydration, take the child immediately to the nearest hospital emergency department.
Some of the symptoms of dehydration in a child include:
- cold skin
- dry mouth
- depressed fontanelle on the skull
- a blue tinge to the skin as the circulation slows
Your baby in hot weatherWater - drinking water
Urine colour chart - dehydration education - Victorian Continence Foundation
To view supporting references to information above, go to: Just Add Water Authors: Dan Negoianu & Stanley Goldfarb - June 2008 Journal of American Society of Nephrology Renal, Electrolyte and Hypertension Division, University of Pennsylvania, Philadelphia, Pennsylvania J Am Soc Nephrol 19: – 2008. doi: 10.1681/ASN.2008030274
Updated 18 November 2013 Disclaimer: Information provided is intended as an introduction to this topic and not meant to substitute for your doctor's or health professional's advice. All care is taken to ensure this information is relevant and applicable to each Australian state. Kidney Health Australia recognises each person's experience is individual and variations do occur in treatment and management due to personal circumstances. Consult a healthcare professional for specific treatment recommendations.