How Much Water Do Your Kidneys Really Need?

Water is essential for your body, and your kidneys rely on fluids to help remove waste from your blood and maintain the right balance of water and minerals.

But there is an important misconception about hydration: more water is not always better and there is no single amount that everyone should drink every day.

Your ideal fluid intake depends on your health, activity level, environment, medications, and kidney function. For some people with advanced kidney disease or kidney failure, drinking too much fluid can actually be harmful.

What Do Your Kidneys Do With the Water You Drink?

Your kidneys continuously adjust the amount of water your body holds onto and the amount it removes through urine.

They also help maintain the balance of important minerals and electrolytes in your blood. When you are adequately hydrated, blood can circulate properly to the kidneys, allowing them to carry out their filtering functions.

When you become severely dehydrated, less blood and fewer nutrients may reach the kidneys. Significant dehydration can contribute to kidney injury.

Does Everyone Need Eight Glasses a Day?

Not necessarily.

You may have heard that everyone should drink eight glasses of water every day. In reality, fluid requirements vary considerably between individuals.

Your needs can be influenced by:

• Age
• Body size
• Physical activity
• Climate and temperature
• Illness
• Pregnancy or breastfeeding
• Vomiting or diarrhea
• Certain medications
• Kidney function
• Heart conditions

The National Kidney Foundation emphasizes that there is no one-size-fits-all amount of water that applies to everyone.

Instead of focusing on a universal number, talk with your healthcare provider about what is appropriate for you.

Dehydration Can Put Stress on the Kidneys

Your body loses fluid in several ways, including through sweating, urination, vomiting and diarrhea.

If too much fluid is lost and isn't replaced appropriately, dehydration can develop.

Possible signs include:

• Increased thirst
• Dry or sticky mouth
• Darker yellow urine
• Tiredness
• Headache
• Urinating less frequently

Severe dehydration can become a serious medical problem and can contribute to kidney damage.

This is especially important during periods of illness, hot weather or strenuous physical activity.

But More Water Isn't Always Better

This is particularly important for people who already have kidney disease.

Healthy kidneys can adjust how much water the body retains or removes. When kidney function is significantly reduced, however, the body may have difficulty removing excess fluid.

People with advanced CKD or kidney failure, including some people receiving dialysis, may therefore need to limit their fluid intake according to their healthcare team's instructions.

Too much fluid can contribute to:

• Swelling
• Shortness of breath
• High blood pressure
• Fluid overload
• Additional stress on the heart

Your prescribed fluid limit, if you have one, should take priority over general hydration advice.

What About Kidney Stones?

Adequate hydration can also play an important role in reducing the risk of kidney stones.

When there is enough water in the urine, stone-forming substances are more diluted, making it harder for crystals to come together and form stones.

People who have previously experienced kidney stones may therefore receive specific hydration recommendations from their healthcare provider.

However, someone with advanced kidney disease or a fluid restriction should not simply increase their water intake without first discussing it with their healthcare team.

Pay Attention When You're Sick

Illness can make maintaining the right fluid balance more difficult.

Vomiting and diarrhea can cause significant fluid loss. Fever and heavy sweating can also increase fluid loss.

If you have kidney disease and become sick, it is important to know what your healthcare team recommends regarding fluids and medications.

Some medicines can also require extra caution when you are dehydrated. For example, certain nonsteroidal anti-inflammatory drugs (NSAIDs) can increase the risk of kidney injury, particularly when taken during dehydration.

Rather than guessing what to do, ask your healthcare provider or pharmacist for a plan you can follow when you become ill.

How Can You Tell If You're Getting Enough Fluid?

Urine color can sometimes provide a useful clue.

For many people, pale-yellow urine generally suggests adequate hydration, while darker yellow urine can be a sign that you may need more fluid. However, urine color is not a perfect measure of hydration and medications, foods, illness, and other factors can affect it.

If you have kidney disease, your healthcare team may give you more specific guidance based on your kidney function and overall health.

Don't Change Your Fluid Intake Based on Internet Advice Alone

One of the most important things to remember is that kidney care is personal.

Advice that is appropriate for a healthy adult may not be appropriate for someone with:

• Chronic kidney disease
• Kidney failure
• Dialysis
• Heart failure
• A history of kidney stones
• Certain electrolyte problems

For some patients, increasing fluid intake is appropriate. For others, fluid restriction is an important part of treatment.

Your healthcare team can help determine which approach is right for you.

Know What Your Kidneys Need

Good kidney care isn't simply about drinking as much water as possible.

It's about understanding how much fluid your body needs and why.

If you have kidney disease, ask your healthcare provider:

• How much fluid should I drink each day?
• Do I need a fluid restriction?
• Should my fluid intake change when I'm exercising or in hot weather?
• What should I do if I develop vomiting or diarrhea?
• Are any of my medications affected by dehydration?

Having these answers before you need them can make managing your kidney health easier.

Kidney Care That Fits Your Life

Managing kidney disease can involve many questions, from laboratory results and medications to diet, fluid intake, and lifestyle changes.

TeleKidney provides virtual kidney care, giving eligible patients an opportunity to connect with kidney specialists without every appointment requiring a trip to a clinic.

If you have questions about your kidney health or your individual fluid needs, speak with your healthcare provider before making significant changes to your fluid intake.

TeleKidney
📞 567-525-3163
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