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Hydration—The First Step to Better Kidney Health

Posted March 30, 2023 by James F. Grow, Jr., M.D. Medical Director

Woman drinking a glass of water

Hydration is key for healthy bodies. Even though it is composed mostly of water, the human body needs water to continue functioning properly—especially your kidneys.

The kidney’s primary function is to filter out waste from the blood and excrete it in urine. Kidneys also perform the following vital functions:

  • Maintain electrolyte levels by regulating sodium and potassium
  • Regulate blood pressure and create red blood cells in the bone marrow
  • Produce vitamin D, which is essential in maintaining healthy bones

But, kidneys can’t do their job well without proper hydration.

A lack of water in the body can lead to a buildup of waste—potentially causing kidney damage. Dehydration also can lead to kidney stones and infections. Sufficient hydration helps prevent stone-forming crystals from accumulating easily and sticking together in the kidneys. Water also helps the kidneys produce more urine to flush out infection-causing bacteria.

SummaCare offers five tips for improved hydration and kidney health.

There is no one-size-fits-all rule when it comes to hydration. We all come in different shapes, sizes, ages and activity levels—not to mention the various climates we live in—so it makes sense our hydration requirements differ, too. Even experts do not agree on the amount of daily fluid needed.

Beverages are not the only way to hydrate. While drinking plenty of water each day is a healthy habit, it’s not the only way to rehydrate. In fact, about 20 percent of dietary hydration comes from foods. Soups, juicy fruits, such as strawberries, cantaloupe and watermelon, and veggies, including spinach, kale, cucumbers and celery, all have high water content that will boost your daily fluid intake. 

Beware, however, foods high in sodium, such as packaged foods and salty snacks, can have the opposite effect. When salt circulates in the blood, the body responds by drawing water out of cells to balance things out, causing dehydration.

Less is more if you have kidney failure. When the kidneys fail and aren’t functioning properly, they can’t excrete enough water, if at all. For patients on dialysis, too much liquid can raise blood pressure and cause other dangerous complications. Dialysis takes over the function of clearing the blood of waste, but it can’t remove excess fluid as often as necessary. That’s why dialysis patients must limit their liquid intake.

It is possible to drink too much water. Surprisingly, it is possible to overhydrate and drink more than your body can flush out. It’s a condition called hyponatremia, where sodium levels in the body become dangerously low. Symptoms of hyponatremia include confusion, nausea, headaches and convulsions. People with underlying conditions, such as congestive heart or kidney failure, as well as endurance or extreme athletes, are at a higher risk for this condition.

Water is the best way to rehydrate. Plain water is the best source of hydration for your body, especially your kidneys. Water has zero calories, no sugar or artificial additives, making it the healthiest option.

So, how do I know if I’m properly hydrated?

Thirst in a good clue to maintaining adequate fluid intake and helps maintain proper body fluid amount. The color and volume of your urine is also helpful in determining adequate hydration. If it’s pale yellow or even clear, and you’re heading to the bathroom once every few hours, you’re likely hydrated. However, if your urine is dark yellow or even brownish, you could be dehydrated.

If you’re wondering what healthy hydration means for you, talk to your doctor about appropriate daily fluid intake for your body and lifestyle. Your provider can review your medical history, health conditions and medications you’re taking to help determine what’s right for you.