Dehydration
What is dehydration?
Water accounts for 50-75% of our body, and forms the basis of our perspiration, urine, digestive juices and blood. Because our bodies can’t store water, we need to ensure we drink enough every day. If we don’t have enough fluid in our body, this is called dehydration, which can cause a range of symptoms. Mild dehydration is easy to manage, but severe dehydration can be serious and may need urgent medical treatment.
Dehydration symptoms
Symptoms of dehydration depend on how dehydrated you are. Symptoms of mild to moderate dehydration include:
thirst
dry tongue, lips and mouth
feeling light-headed and dizzy
headache
urine that is darker than usual
not passing as much urine as usual.
Symptoms of severe hydration can include:
excessive thirst
extremely dry mouth
fast breathing
elevated heart rate
lowered blood pressure
fever
little or no urine
feeling irritable, drowsy and confused.
Babies and young children can have different symptoms, depending on their age. They can include:
no tears when crying
dry nappies
sunken eyes or cheeks
sunken soft spot (on top of the skull)
irritability
drowsy and listless.
What causes dehydration?
Dehydration can be caused by a range of different things including:
excessive sweating due to exercise or hot weather
vomiting and diarrhoea
having a fever
drinking too much alcohol
some medications, such as diuretics and some blood pressure medications
increased urination due to diabetes complications
not drinking enough water.
Who is at risk of dehydration?
While anyone can become dehydrated, some people are more at risk than others. For example:
infants and children, as they are more likely to have vomiting and diarrhoea and may be unable to say they are thirsty or get their own drink
older adults, due to smaller fluid reserves as they age and decreased mobility limiting their ability to get drinks
people with chronic illnesses such as diabetes and kidney disease
people who work outside or who are exposed to excessive amounts of heat such as welders, bakers, and dry cleaners
athletes or people who perform lots of exercise.
Is dehydration dangerous?
Dehydration can lead to serious complications including:8
heat exhaustion and heat stroke
urinary and kidney problems such as urinary tract infections (UTIs), kidney stones or kidney failure
seizures
low blood volume shock (hypovolemic shock) which causes a drop in blood pressure and oxygen in your body.
If left untreated, dehydration can be fatal.
Treatment for dehydration
If you are mildly dehydrated, the best treatment is to:
move to a cool place
loosen any tight clothing
remove unnecessary clothes
drink small amounts of water, often.
Oral rehydration solutions available from your pharmacy can also be helpful, especially after vomiting and diarrhoea. These are a mixture of electrolytes (salts) and carbohydrates (sugar) dissolved in water which are used to replace lost fluid and salts. Your pharmacist can advise you on which preparation is most suitable.
Severe dehydration may be treated in hospital where you will be given fluids through a drip.
How to prevent dehydration
You can prevent dehydration by taking the following steps:
drink plenty of water and eat foods that contain water, such as fruits and vegetables
hydrate before, during and after strenuous exercise
avoid exercising in hot conditions
drink more water on hot or humid days when you are likely to sweat more
use oral rehydration solutions at the first sign of vomiting and diarrhoea
drink extra fluids when you’re sick.
When to see your doctor?
It’s important to seek medical attention when symptoms indicate severe dehydration. You should also seek medical advice if you have taken steps to treat mild or moderate dehydration and symptoms persist.
If you have a young child, you should call your doctor if they:
vomit more than a few times in 24 hours
haven’t drunk anything for a few hours
are under 12 months and are not drinking breastmilk or formula
have vomit that is green, red or brown
have signs of dehydration
don’t seem to be improving despite giving fluids.
How much water should you drink each day?
The Australian Dietary Guidelines recommend that we drink plenty of water each day.11While this will vary each day, the following are recommendations based on age.
Children 0 – 3 years
Up to 1 litre (4 cups) – this can include breastmilk and formula for children under 12 months
Children 4 – 8 years
1.2 litres (5 cups)
Children 9 – 13 years
1.4 – 1.6 litres (5-6 cups)
Teens 14 – 18 years
1.6 – 1.9 litres (6 – 8 cups)
18 years and over
2.1 – 2.6 litres (8-10 cups)
Tips to drink more water
It’s easy to forget to drink water so here are some tips that may help.
Make water your drink of choice
Have a bottle of water on your desk or carry one with you when you go out
Drink a glass of water with each meal and snack
Add fruits and vegetables to your water for different flavours
Drink sparkling water for variety.
Your local MediADVICE pharmacist is available to help you manage your health. We have a range of oral rehydration solutions suitable for everyone in the family and can provide advice on medication and other products to help you stay hydrated. We can also refer you to a doctor if necessary.
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General advice only – this information should not replace the information provided to you by your health care professional. If symptoms are severe or persist, please speak to your health care professional. Information current as of date of publishing.