How Long Does It Take To Rehydrate?

Staying hydrated is one of the most important aspects of our health. It’s vital for our organs to function correctly, for concentration levels, to help regulate our temperature, support immunity, aid weight loss and give our cells nutrients. 

We often struggle to remain hydrated. We’re told to drink enough water a day but we’re always tempted to drink coffee, beer or soda instead – some of which dehydrate us further. 

So, when we are trying to rehydrate ourselves, the question we might ask ourselves is – how long does it take?

How Long Does It Take To Rehydrate

To answer this, we’ve written a helpful guide below which should give you all the information you’re looking for. 

How long does it take to rehydrate?


It’s not a simple answer to give. There can be many factors to hydration. As a general rule, it can take 5 minutes to start rehydrating your body – but it’s not a rule. 

If you have an empty stomach, your body will easily digest water and the hydration process will be quickened.

However, if you’re drinking water as you’re eating – your body will prioritize the digestion of food over water, meaning it could take up to 2 hours for your body to begin the rehydration process. 

The other factors of hydration include your size and weight, how dehydrated you are, what you’re drinking to combat dehydration, if you’ve been exercising, if you’re fighting illness or infection, the climate and if you’re recovering from surgical procedures.

All of these factors can play a role in the rehydration process, but it will still alter from person to person. As a general rule, you can expect to rehydrate fully from 2 glasses of water. 


There are many reasons why a person might become dehydrated, but the obvious one is that they have not consumed the correct amount of fluid required for their body to function correctly. 

A study has suggested that, in an average climate – a man should have around 3-4 liters of fluid and a woman should have 2-3 liters of fluid a day. It’s important to know this includes fluid consumed from both food and drink. The ratio for this should be around 80:20 in favor of fluids. 

If you become dehydrated and you do not act quickly, you could end up with chronic dehydration and that’s when things become really serious.

Our bodies can only take so much punishment. Yes, we can go weeks without food but usually only 3 days without fluid. 

Symptoms Of Dehydration 

The symptoms of dehydration will differ depending on how dehydrated the person is. If you’re mildly dehydrated, you could expect to experience:

  • Headaches and migraines 
  • Dry mouth
  • Increase in thirst 
  • Dry skin 
  • Unusual lack of urination 
  • Constipation 
  • Feeling dizzy 
  • Inability to produce tears 

Whereas, if you’re extremely dehydrated, you may experience:

  • Extreme or severe thirst 
  • Increased and rapid heart rate
  • Very low blood pressure 
  • Very dark urine production 
  • Lack of sweat 
  • Tired-looking eyes 
  • Extreme fatigue 
  • Dry, shriveled or tight-looking skin  

When your body starts to become dehydrated, the following things may occur:

Decrease In Plasma Levels

Plasma cannot maintain the blood cells if there is insufficient hydration to do so. Plasma is the liquid make-up of the blood itself. 

The Heart Works Too Much 

The heart has to work much harder to provide the fuel to our body than normal, which is caused by the reduction of plasma and the production of much thicker blood. 

The Brain Isn’t Right 

You’ll likely struggle to remember things and feel confused – which is caused by the lack of fluid to the brain tissue. This is likely the reason why the severely dehydrated often faint – as the brain needs to defend itself from long term damage and needs to start up from scratch. 

The Skin Is Affected 

Dehydration will make the body try and absorb liquid from any potential source that isn’t a vital organ to try and provide for the areas that need it.

So the body may take liquid from the skin and give it to the kidneys for example. This leads to dry and strange looking skin. This is also the reason for a lack of sweat, tears and urine. 

What To Do When Dehydrated

You’ll want to get a source of fluids as soon as possible. If you’re in a hot climate, it’s important to get out of direct sunlight immediately.

The reason for this is that if you get sunburn, your body becomes dehydrated much quicker than normal. Moreover, the more you sweat in sunlight – you’re more likely to get dehydrated too. 

A source of fluid can include things like:

  • Water
  • Sports drinks 
  • Tea/coffee 
  • Milk
  • Watermelon 
  • Grapes
  • Berries
  • Lettuce
  • Cabbage 
  • Oranges 
sources of fluid
Juices as source of fluid

In serious survival situations, literally anything that can provide you with hydration will be useful including things like cacti, animals, rainwater, urine, animal dung etc. Hopefully, you’ll never have to experience this – but it’s worth noting.

Preventing Dehydration 

Prevention is the key when it comes to fighting dehydration. It’s important to remain hydrated throughout the day by sipping water several times as you go about your business. Choose foods that don’t have an excessive amount of salt, as this can make you more dehydrated. 

It’s important if you are ever stuck for a fluid source, that you do not drink contaminated water or sea water.

Contaminated water may lead to diarrhea and vomiting, which can also come with excessive sweating. All of these will cause further dehydration. 

If you are fit and active, it’s important to take liquids with you to your exercises and remember to drink it when required. 

What Not To Do When Dehydrated 

Some people may think when they’re dehydrated that chugging water will get them hydrated faster, but this simply isn’t true and could actually do the opposite. 

By doing so, you might end up diluted your blood, causing quicker urine production, causing water intoxication or vomiting. 

The Take-Away 

There isn’t a definitive answer of how long it will take for you to rehydrate as it depends on a multitude of factors. The important thing to remember is to remain hydrated throughout the day and you won’t need to worry about the time. 

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