The Scientist: Roxanne Sukol, M.D., Medical Director of the Cleveland Clinic’s Wellness Enterprise.
The Answer: Our bodies are made up primarily of water, which is vital to pretty much every system we have—digestive, circulatory, you name it. When your immune system is working hard to fight off a bacterial or viral infection, metabolism increases and your body goes into hyperdrive. You’re like a car with the pedal to the metal, engine racing, and water is your Premium Unleaded. You need more of it to keep going.
Meanwhile, you’re losing the very resource your body so desperately requires. If you have a fever, your body sweats to cool itself down, depleting your fluid supply. If you’re coughing and sneezing, you’re wasting water by literally spewing it out of your mouth and nose. (See this dramatic photo.) Diarrhea and vomiting expel liquid in their own special ways.
And on top of all that, appetite often decreases when you’re feeling under the weather, so you’re taking in less water than normal from food.
It all adds up to an empty tank, whether you realize it or not. When you’re sick, don’t wait until you feel thirsty. You could be dehydrated and not even know it.
You can get along without food for a couple of days if you’re not feeling well, but you must drink, even if you don’t want to! It doesn’t have to be plain water. Tea and broth are great. Juice with vitamin C will help your immune system, but you should dilute it to cut down on the high sugar content, which can actually hinder immunity. Sports drinks aren’t the best choice—they’re also super sugary and full of additives—but Pedialyte is one way to get the fluids and electrolytes your body craves. Milk…soda…really, anything liquid will do the trick. Lay off booze, though, since that will only dehydrate you more.
If you’re really nauseous and drinking a lot is difficult, take a teaspoon of liquid every minute or so. You can absorb water through the tissues of your mouth, even if it doesn’t get all the way down to your stomach.