HEALTH CONDITION

Dehydration

Dehydration means your body loses more fluids than you take in. If it's not treated, it can get worse and become a serious problem.

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

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

Source: NHS, last reviewed 01 May 2026. Contains public sector information licensed under the Open Government Licence v3.0.

This page is general information and is not medical advice. It does not replace a registered doctor, and it is not a prescription or a recommendation to use any medicine or test. Prices are listed prices and may change. Always follow the advice of your doctor or pharmacist.