Dehydration

Important

Babies, children and older adults are more at risk of dehydration.

Symptoms of dehydration

Symptoms of dehydration in adults and children include:

feeling thirsty
headache and feeling light-headed
dark yellow, strong-smelling pee
peeing less often than usual
feeling dizzy or lightheaded
feeling tired
a dry mouth, lips and tongue
sunken eyes

Signs of dehydration in a baby may include:

a sunken soft spot (fontanelle) on top of their head
sunken eyes
few or no tears when they cry
fewer wet nappies than usual
being drowsy or irritable

Causes of dehydration

Dehydration can happen more easily if you:

have diabetes
have been sick or have diarrhoea
have been in the sun, or a hot environment, too long (heatstroke)
have drunk too much alcohol
sweat a lot after exercising
have a high temperature
take medicines that make you pee more (diuretics)
rely on other people to get you drinks

Things you can do to treat dehydration

You should drink fluids if you have symptoms of dehydration.

If you feel sick or have been sick, you may find it hard to drink, so start with small sips and then gradually drink more. Avoid caffeinated drinks and alcohol as both will dehydrate you.

A pharmacist can help with dehydration

If you're being sick or have diarrhoea and are losing too much fluid, you need to put back the sugar, salts and minerals your body has lost.

A pharmacist can recommend oral rehydration solutions. These are powders that you mix with water and then drink.

Ask your pharmacist which rehydration solutions are right for you or your child.

Find a pharmacy

Ask for an urgent GP appointment or get help from NHS 111 if:

you're feeling unusually tired (or your child seems drowsy)
you feel dizzy when you stand up and it does not go away
you have dark yellow pee or you're peeing less than normal (or your baby has fewer wet nappies)
you or your child are breathing quickly or have a fast heart rate
your baby or child have few or no tears when they cry
your baby has a soft spot on their head that sinks inwards (sunken fontanelle)

These can be signs of serious dehydration that need urgent treatment.

You can call 111 or get help from 111 online. Call 111 if you need advice for a child under 5 years old.

Call 999 or go to A&E if:

You or somebody else has signs of dehydration and:

blue, grey, pale or blotchy skin, lips or tongue - on brown or black skin, this may be easier to see on the palms of the hands or soles of the feet
skin that feels cold
difficulty breathing, or is taking lots of quick breaths
are confused
are sleepier than normal or difficult to wake

These could be signs of shock, which is a serious complication of dehydration.

Find your nearest A&E

Do not drive to A&E. Ask someone to drive you or call 999 and ask for an ambulance.

Bring any medicines you take with you.

Keeping your child hydrated

Once dehydration has been treated, it's important that your child's fluid levels are maintained.

Do

carry on breastfeeding your baby or using formula - try to give small amounts more often than usual
give your baby small sips of extra water if they're on formula or solid foods (if your baby is under 6 months, then boil the water first before letting it cool)
give regular small sips of rehydration solution to replace lost fluids - ask your pharmacist to recommend one
give small children their usual diet

Don't

do not make formula weaker
do not give young children fruit juice or fizzy drinks - it can make diarrhoea or vomiting worse

How to reduce the risk of dehydration

Drinking fluids regularly can reduce the risk of dehydration. Water or diluted sugar-free squash are good choices.

You should drink enough during the day so that your pee is a pale colour.

Drink more when there's a higher risk of dehydrating. For example, if you're being sick, sweating due to hot weather or exercise, or you have diarrhoea.

Children under the age of 5 and older adults should get plenty of fluids as they have an increased risk of dehydration.

Helping someone you care for

A person you care for may not have a sense of how much they're drinking.

You can help them by:

making sure they drink at mealtimes
making drinking a social thing
offering them food with a high water content - for example, soup, ice cream, jelly and fruits like melon
making sure they have access to fluids at all times

Video: How to prevent dehydration

This video shows you how you can reduce the risk of dehydration.

Media last reviewed: 12 May 2026
Media review due: 12 May 2029

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