Water makes up about 78% of our body, so it's hardly surprising that we react with other symptoms of dehydration when the amount coming out starts to be more than what's coming in.
Dr Amir Khan, who regularly appears on ITV's Lorraine and is woman&home's resident GP, says, "You should drink straight away if you feel thirsty, but there are other more subtle ways your body may tell you that you need to increase your fluid intake." This can be through water, but lower-fat milk, sugar-free drinks, tea, and coffee all count too, according to the NHS. Hydrating foods are a good option as well.
The symptoms of dehydration can disguise themselves as other summer ailments, so keep a lookout for these signs. Try to stay hydrated throughout the day, and if you feel unwell, always seek medical advice.
Symptoms of dehydration
1. Bad breath
Bad breath is perhaps one of the more discreet symptoms, says the doctor. It's very common but you may only notice it yourself at certain times of day, particularly the morning.
"Dehydration reduces saliva production, which normally helps wash away bacteria in the mouth. Less saliva means more bacterial growth, leading to bad breath," he explains.
When you're asleep overnight, the body doesn't get the chance to drink fluids. which is why it's important to drink water first thing in the morning - before your cup of coffee.
2. Muscle cramps
Dr Khan says muscle cramps are caused by a disruption in the “balance of electrolytes like sodium and potassium, which are essential for normal muscle contraction”. This imbalance can lead to painful cramps.
You might be more likely to experience these cramps if you’re exercising during hot weather and sweating a lot, and many people get them during the night.
There are benefits of exercising in the heat, but to help prevent dehydration, you should exercise in the cooler parts of the day, drink more water than you usually would during a workout, and drink a sports drink with electrolytes.
3. Feeling tired all the time
It's difficult to sleep in the heat, but if you do get enough sleep and still feel tired or lethargic, it's a sign you need to drink more water.
This symptom of dehydration occurs when there is less blood volume in your body due to a decreased amount of fluid in your blood. “This means your heart has to work harder to pump oxygen and nutrients to your muscles and brain. At the same time, less water in your cells slows down essential chemical reactions involved in energy production, leaving you feeling sluggish and fatigued,” he says.
Mild dehydration can also disrupt your sleep at night, causing you to wake up in the middle of the night and find it difficult to get back to sleep.
Aiming to drink the recommended six to eight cups of water a day will help prevent this, according to the NHS. Hot temperatures can also make you feel more tired and low in energy, so try to avoid being outside at the hottest time of day and stay in cool places where you can.
4. Headaches
As your brain contracts from fluid loss, it can cause a headache, the doctor explains. Once properly hydrated, your brain will return to its normal state, and the headache should ease.
You might be more susceptible to a headache if you’ve been exercising in the hot sun and not drinking enough water. Always make sure you wear a hat and try to stay in the shade if you can.
5. Dry skin
As the body struggles to get enough water to our skin when we're dehydrated, our skin can start to dry out, the doctor says.
If your skin is dehydrated, you might find your lips feel chapped and your skin feels itchy, tight, or particularly sensitive. If you wear makeup, you'll likely see that it doesn't apply quite as evenly or easily.
6. Constipation
Similarly, one of the causes of constipation is dehydration, as without enough water, the digestive system can't function properly. There's not enough electrolytes and fluids making their way to the gut, says Dr Khan.
You'll also notice your urine is a much darker colour. "A good rule of thumb is if your urine is a pale yellow colour, then you are likely to be well hydrated," he says.
What's the fastest way to fix dehydration?
The fastest way to fix dehydration is by adding electrolytes back into your body, which are lost through sweat and other cooling processes at a faster rate when it's hot outside. These are present in certain foods, such as spinach, bananas, and coconut water. You can also buy electrolyte powders to add to your water.
However, the best way to fix dehydration is to pre-empt it. "Dehydration is a condition where you lose so much body fluid that it can't function normally. It occurs when you lose more fluids than you take in," the doctor explains. "So, drinking water regularly throughout the day is vital."
Six to eight glasses of water are ideal, "but if the weather is hot or you are more active, then aim for more," he says.
