Dehydration

Dehydration happens when your body loses more fluid than you take in, and it can become serious if it isn't treated. Drinking fluids regularly, such as water, diluted squash or fruit juice, can prevent it.

Dehydration can show itself in several ways. In an adult, you may notice:

• feeling thirsty
• dark yellow, strong-smelling pee (urine)
• peeing less often than usual (less than 3 or 4 times a day)
• feeling dizzy or lightheaded
• a headache
• feeling tired
• a dry mouth, lips and eyes
• sunken eyes

A baby may be dehydrated if they have:

• a sunken soft spot (fontanelle) on their head
• sunken eyes
• few or no tears when they cry
• a dry mouth
• fewer wet nappies
• dark yellow pee
• drowsiness or irritability
• fast breathing
• cold and blotchy-looking hands and feet

Speak to a doctor urgently if:

• you're extremely thirsty
• you're feeling unusually tired (or your child seems drowsy)
• you're confused and disorientated
• you feel dizzy when you stand up and it does not go away after a few seconds
• 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 has few or no tears when they cry
• your baby has a soft spot on their head that sinks inwards (sunken fontanelle)
• your baby has vomited 3 times or more in the past 24 hours
• your child has had 6 or more episodes of diarrhoea in the past 24 hours
• your symptoms continue even after drinking fluids
• you think your baby or toddler is dehydrated

If the doctor's chamber is closed, phone a doctor or the 16263 health line.

If your doctor suspects dehydration, you may need a blood test or a urine test. These check the balance of salts in your body.

Dehydration happens when you don't drink enough fluid, or when you lose more fluid than you take in. Your body loses fluid through sweat, vomit, pee or diarrhoea.

Causes of dehydration include:

• illness, for example gastroenteritis, where you lose fluid through diarrhoea and vomiting
• sweating too much, for example due to a fever, exercise, or manual work in high temperatures
• drinking too much alcohol, because it makes you pee more (a hangover headache is a sign you're dehydrated)
• diabetes, where high levels of glucose in your blood make you pee more

Anyone can become dehydrated, but some people are more at risk:

• babies and infants, because their low body weight makes them sensitive to even small amounts of fluid loss
• older people, because they may be less aware they're becoming dehydrated and need to drink fluids
• people with a long-term health condition, such as diabetes or alcoholism
• athletes, because they can lose a large amount of body fluid through sweat when exercising for long periods

You can become overhydrated while exercising, a condition also called hyponatremia. It happens when the salt level in your blood drops too low, and it can occur if you drink too much water over a short period of time.

Athletes are sometimes affected. They lose salt through sweat, and then the salt that's left gets diluted when they drink large amounts of water.

The symptoms of overhydration are feeling sick, vomiting and headache. In serious cases, the brain can swell. This can cause confusion, seizures and coma, and in rare cases it can lead to death.

If you're worried that you may be overhydrated, see a doctor and get medical advice.

If you're dehydrated, drink plenty of fluids such as water, diluted squash or fruit juice. These work better than tea, coffee or fizzy drinks.

If you're being sick and finding it hard to keep water down, try drinking small amounts more often.

When you're dehydrated, you lose sugar and salts as well as water. Oral rehydration solutions can help put this right. They come as powders that you mix with water and then drink, and they contain a mixture of potassium and sodium salts, along with glucose or starch.

Ask your pharmacist or doctor which rehydration solution is right for you or your child.

Give your baby plenty of liquids, such as breastmilk or formula. Smaller amounts of fluid given more often can work better.

If you use formula, don't dilute it. Babies who are formula-fed and those who are on solids can be given extra water.

Try to avoid fruit juice, particularly if your baby has diarrhoea and vomiting, because it can make things worse.

Give regular sips of oral rehydration solution (a few times an hour) alongside their usual feed of breastmilk, formula milk and water. This helps replace the fluids, salts and sugars your baby has lost. Ask your pharmacist for advice.

Don't give an infant or child with dehydration only water. Water can dilute the already low level of minerals in their body and make the problem worse. Give them diluted squash or oral rehydration solution instead, and ask your pharmacist for advice.

If your child is finding it hard to keep fluid down because of vomiting, give small amounts more often. A spoon or a syringe into their mouth can make this easier.

If severe dehydration isn't treated straight away, it can lead to serious complications. It needs treatment in hospital. There, you'll be put on a drip so the fluid your body has lost is replaced quickly.