MiBlueDaily
Jake Newby
Nov. 15, 2025
Growing up you probably heard the same advice over and over when you were sick: drink plenty of fluids.
Have you wondered why this is such common advice and why hydration plays such a huge role in battling a cold or the flu? Here is the science behind it.
How Does Hydration Help With Being Sick?
We constantly need to replenish things we lose, and water consumption is no different. When you eat all your food, you have to get more groceries. When your car runs low on gas, you have to fill it back up. We get dehydrated when our body loses more fluid than it absorbs, so when your body loses water – which it does when you sweat, urinate and even exhale – you need to replace what you lose because your body relies on water to function properly.
When we’re sick, we lose more fluid than you might think. Fever-induced sweating, sweating while trying to sleep, coughing, vomiting and diarrhea all expel water from your body. And even small fluid imbalances can cause you to feel dehydrated, which can increase body temperature and make you feel hot. Proper water intake regulates your internal body temperature.
Research shows proper hydration, through water and electrolyte replenishment, helps keep mucus thin and clear, allowing it to better protect you from germs, according to the Cleveland Clinic.
According to the Mayo Clinic, water also helps you get and stay healthy by:
- Carrying nutrients and oxygen to cells.
- Dissolving nutrients in the bloodstream to make them accessible to the body.
- Lessening the burden on the kidneys and liver by flushing out waste products.
- Lubricating joints.
- Moistening tissues in the eyes, nose and mouth to loosen up stuffiness and congestion.
- Protecting organs and tissues.
Drinks to Consider and Drinks to Avoid While Sick
Water is the most effective hydration option. If you want to liven up your h2O, add some lemon for a vitamin C boost.
Beyond that, electrolyte solutions like Pedialyte® can replenish your body with the water and electrolytes it loses when you vomit or have diarrhea. But these drinks should be consumed in small amounts as overdoing them could lead to an electrolyte imbalance, which could worsen your symptoms.