What is Dehydration and What are its Symptoms?

What is Dehydration and What are its Symptoms?

Dehydration Causes, Effects, and Symptoms


Have you drunk enough water today? If you aren’t drinking enough then hydration could be a real problem for you, especially if you get sick.


Dehydration can affect anyone, young, old, and in between, basically everyone except mermaids, and it may be more common than you’d think!


Let’s take a look at what dehydration is, what causes it, and all of the nasty effects it can have on your body.



What is dehydration?


Dehydration happens when your body isn’t getting enough fluids, or if you’re losing more fluids than you’re taking in.


Your body needs water to function properly, as it plays a part in all the essential systems that keep your body moving, including helping your digestive system, flushing out waste and toxins, and lubricating your joints and eyes.


When you’re dehydrated all these everyday functions can be affected, making you feel unwell, tired, and thirsty.


The NHS’s Eatwell Guide recommends that you should drink 6 – 8 cups or glasses of water every day to help you to remain well hydrated and to keep your body working at its best.



What are the symptoms of dehydration?


It would be easy to write off dehydration as simply feeling a bit thirsty, but the reality is that it can do so much more to your body than that!


In fact, your body feels thirsty just to remind you to drink enough fluids so it can function properly, clever, right?


When you’re dehydrated there are lots of unpleasant symptoms you may experience, with some of the most common including:


  • Feeling thirsty
  • Headache
  • Tiredness
  • Feeling dizzy or lightheaded
  • Peeing less often than usual or less than 4 times a day
  • Strong smelling or dark yellow pee
  • Dry mouth, lips, and eyes



Signs of dehydration in babies


Babies and young children can be vulnerable to dehydration, as their smaller bodies can make a smaller loss of fluid more impactful.


On top of this, babies won’t be able to tell you if they’re feeling thirsty, dizzy, or lightheaded, so it’s up to you to spot their symptoms for yourself.


Some of the most common symptoms of dehydration in little ones include:


  • Dry mouth
  • Dry nappy
  • Dark yellow pee
  • No tears when they cry
  • Tiredness
  • A sunken, soft spot on their head (fontanelle)
  • Breathing quickly
  • Hands and feet feel cold or look blotchy


If you’re looking after a child who is younger than 5 and they are experiencing any of these symptoms or have not peed within the past 12 hours, take them to see a doctor or to A&E immediately.


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Signs of dehydration in the elderly


Elderly people are another group that may be more vulnerable to dehydration.


Some older people may not be aware that they are drinking less than they should as their sense of thirst may be reduced, and they may need encouragement to keep their fluids up.


Some of the most common signs of dehydration you can look for in elderly people include:


  • Dry mouth, lips, or tongue
  • Dry or sunken eyes
  • Dry skin
  • Tiredness
  • Feeling dizzy or lightheaded
  • Low blood pressure
  • Confusion or disorientation



What causes dehydration?


Dehydration usually happens if you’re losing more fluids than you’re taking in, so anything that makes you lose fluid can cause dehydration.


This can include illnesses, exercise, sweating in hot weather, or even some medical conditions.


Some of the most common causes of dehydration include:


  • Vomiting
  • Diarrhoea
  • Excessive sweating
  • Drinking too much alcohol, which is a diuretic and makes you pee more often
  • Diabetes – your kidneys try to clear excess glucose from your blood by producing more urine



Diseases that cause dehydration


If you catch a disease or illness that makes you throw up or gives you diarrhoea, then you could be at risk of dehydration.


You could also become dehydrated if you catch an illness that causes a high fever, as your body could sweat out more fluids than you’re drinking.

Goodness knows you don't want to be stuck with another problem on top of your illness, so make sure you get a drink down you!


Some common illnesses that can cause diarrhoea, vomiting, or high temperatures include:


  • Gastroenteritis
  • Norovirus
  • Rotavirus
  • Food poisoning
  • Flu



What are the effects of dehydration on the body?


Two-thirds of your body is made up of water, so when you’re dehydrated it can cause a major impact on how your body functions.


For starters, dehydration can affect your kidneys, which rely on water to filter out toxins and product water.


If you’re dehydrated, you may experience more urinary tract infections (UTI’s) than usual as your kidneys and urinary tract struggle to function at their best.


If you’re not drinking enough you may also experience constipation, as your poo may become harder and more difficult to pass if your bowels aren’t properly hydrated.


Basically, if you want your toilet time to be as comfortable as possible, make sure you hydrate!


Can dehydration affect my blood pressure?


Dehydration can affect your blood pressure, which can cause some of the common symptoms of dehydration.


When you’re dehydrated, it can lower your blood pressure, which in turn can cause light-headedness, dizziness, and even fainting in some circumstances.


This can also happen in those who take diuretics to manage high blood pressure if they don’t remember to drink more fluids to make up for the fact that they need to pee more often.



How to treat dehydration


The easiest way to treat dehydration is to drink plenty of fluids, especially water.


If you’re not a big fan of water, you can also drink diluted fruit juice, low-fat milk, tea, or coffee to keep your fluid levels up.


However, you should be aware that drinking lots of sugary drinks, including fruit juice and smoothies, can have an effect on your teeth and that caffeinated drinks like tea and coffee may need to be limited, especially if you’re pregnant.


Another popular and effective way to treat dehydration is to use an oral rehydration treatment.


What is oral rehydration treatment?


Oral rehydration treatments are given to those who are suffering from dehydration to help increase their fluid levels.


They also help replace the essential salts, sugars, and minerals that are lost from your body when you’re dehydrated, helping to restore the healthy balance in your bodily fluids.


Oral rehydration treatments are often available in sachets or tablets that are dissolved in water so you can drink it right away.


These drinks come in different flavours and can be taken by children as well as adults, although you’ll need to ask your doctor or pharmacist before giving any treatment to a young child.



What if I suffer from dehydration in pregnancy?


Dehydration can be an issue during pregnancy, especially if you’re suffering from morning sickness and aren’t drinking enough fluids to replace what you’ve lost while throwing up.


If you’re worried about dehydration during pregnancy, the best thing you can do is remember to drink little and often throughout the day, and make sure you drink your 8 glasses a day at least.


If you still have concerns, speak to your doctor, pharmacist, or health visitor and ask for their advice.



When should I see a doctor?


You can usually treat mild dehydration at home, but if it becomes severe you should see a medical professional as soon as possible.


You should go to A&E or call 999 if you experience any of the following symptoms:


  • Feeling unusually tired
  • Feeling confused or disoriented
  • Dizziness when you stand up that doesn’t go away
  • A weak or rapid pulse
  • Having fits or seizures
  • You haven’t peed all-day



Well, if all that didn’t make you want to drink your 8 glasses of water a day then nothing will!


If you have any more questions about dehydration and how to keep your fluid levels up, remember that our friendly pharmacy team are available to answer all your questions any time.


Laura Henderson - Medical Content Writer
James O'Loan - CEO & Superintendent Pharmacist
James O'Loan , CEO & Superintendent Pharmacist on 17 September 2021
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