What Does Dehydration Feel Like?

While it may be more common in the heat and humidity of summer, dehydration can occur at any time of year, when your body doesn’t have as much fluid as it needs.

However, thirst isn’t always a reliable indicator of dehydration. In fact, many people might not know what dehydration feels like, dismissing its symptoms as something else entirely.

In most cases, dehydration is nothing to worry about and can be treated by drinking plenty of fluids. But, if left untreated because you don’t know what dehydration feels like, it can become a serious problem.

In this article, we'll talk through what dehydration feels like, how to treat dehydration at home, as well as how to treat dehydration in infants.

What does dehydration feel like?

Dehydration occurs when your body loses more fluid than it's able to take in. As our bodies need water for expelling waste, maintaining body temperature, and protecting organs, a lack of it can cause a range of painful and distressing symptoms.

For example, it's quite common to experience physical changes with dehydration. White tongue, sunken eyes, and flushed skin are all common symptoms of dehydration to look out for, and you may experience a feeling of nausea too. Thirst is also a tell tale sign of dehydration, this is the brains way of warning you that you may be lacking fluids.

In terms of what dehydration feels like, there are five key symptoms of dehydration that you should be aware of:

1. Feeling dizzy or lightheaded

You may notice you feel dizzy or lightheaded with dehydration and, in some cases, you may even feel faint.

Feeling dehydrated can often feel like you have a spinning sensation in your head, as if you or your surroundings are moving. You may also feel unsteady on your feet or struggle to focus properly.

Lack of fluids in the body leads to a decrease in blood volume, causing you to feel dizzy or lightheaded. When blood levels drop, blood flow to the brain reduces too, which means your brain doesn’t receive enough oxygen. This leads to that discomforting dizziness.

2. Headaches and migraines

Dehydration can trigger migraines and headaches as well. This is because dehydration causes tissue in your body to shrink and contract. As this happens, your brain starts to pull away from the skull slightly, putting pressure on the nerves and causing pain.

A dehydration headache feels like a dull and throbbing ache across your forehead, sometimes leading down to your temples. This may get worse when you move or shake your head.

However, a dehydration migraine often occurs on one side of the head and the pain may feel more intense. A dehydration migraine may be accompanied by other symptoms as well, such as nausea, dizziness, and a sensitivity to light, sound, or even smells.

3. Feeling tired

Another common symptom of dehydration is feeling tired and fatigued, with your body needing sufficient fluids to stay energised in the first place.

Blood pressure can drop when your body doesn’t have enough fluid, resulting in your brain not receiving enough blood flow. This can cause you to feel sleepy, fatigued, or low in energy.

4. Dryness around lips, mouth, and eyes

Dehydration can also significantly impact your skin health, particularly around your lips, mouth, and eyes.

For example, when you feel dehydrated, your tongue might turn a whiter shade, your eyes may look hollow and sunken, or your lips will start to crack. As your symptoms worsen, you may also develop mouth ulcers, flaky skin around your eyes, or even blurry vision.

These symptoms of dehydration occur when your skin doesn’t get enough water and, therefore, cannot maintain its natural processes.

5. Changes to urine

Alongside visual changes to urine, there may also be some physical discomfort with symptoms of dehydration.

Your body requires fluids to help flush out toxins and excess minerals. However, with dehydration, this process is disrupted. As the body can’t expel what it needs to, your urine becomes more concentrated, which can cause irritation to the bladder lining.

As a result, the colour of your urine is a common indicator that you’re feeling dehydrated. If your urine is a clear to pale yellow, then you have enough fluids. However, should your urine look darker or more amber in tone, then this is another symptom of dehydration.

How to treat dehydration at home

The fastest way to cure dehydration at home is by drinking plenty of water and avoiding drinks that can actually cause dehydration.

The NHS recommends that you drink six to eight glasses of water per day. And while tea and coffee are typically included within this quota, the caffeine levels in both can be quite dehydrating. However, you can try decaffeinated tea and coffee as an alternative. It’s also best to stay away from alcohol when looking to treat dehydration at home, as alcohol can dehydrate your body even further.

You can also help treat dehydration at home by eating more water-based fruits and vegetables as well. For example, watermelon is 92% water, which means you can hydrate your body with one of your five a day. You can also try cucumber, tomato, strawberries, and lettuce for the same effect. But do consider these as additional – not an alternative - to drinking more water to treat dehydration at home.

How to treat dehydration in infants

As they might struggle to communicate when they’re thirsty, dehydration in infants is quite common. If you’re looking for these signs of dehydration, your infant might shed no tears when crying, have a dry or sticky mouth, or be urinating much less frequently. When your infant does pass urine, you may notice it has a darker colour and stronger smell.

It's particularly common for infants to experience dehydration when they are sick or dealing with illnesses, such as persistent vomiting reflux. If you’re looking to treat a dehydrated infant, keep in mind this requires different steps than treating an adult.

If you're breastfeeding an infant, it's safe to continue this. However, try to feed them smaller amounts in more frequent doses than their regular feeding schedule. Infants don’t typically need extra water alongside breastmilk.

To avoid displacing the nutrients of formula, it's not advisable to routinely give water to your formula-fed infant of 6 months or under. However, in dealing with dehydration in your infant, it's safe to give them sips of plain, boiled, and cooled water on top of their usual formula feeds. Be sure to check the temperature of the boiled water is sufficiently cooled before feeding.

It's always best to see a medical practitioner if you're concerned about dehydration in your infant, as they can advise on appropriate rehydration fluids and treatments

Explore our Be Healthy hub for more advice to help you look after your wellbeing. We’ve got articles on foods to boost low energy (which may be caused by dehydration), as well as advice on how to manage dry skin caused by conditions like eczema.

Medically reviewed in March 2024.