Your Kidneys Filter 150 Quarts Daily—Here's Why You Should Know If Yours Are Struggling

Your kidneys work around the clock, filtering approximately 150 quarts of blood every single day to keep toxins from building up in your system. When these vital organs start struggling, the effects ripple throughout your entire body—yet more than 1 in every 7 adults in the U.S. has some level of chronic kidney disease (CKD) without realizing it.

Why Don't People Know They Have Kidney Disease?

The silent nature of chronic kidney disease makes it particularly dangerous. "People with chronic kidney disease generally have no symptoms until they're very near kidney failure," explains Dr. Michael Shlipak, a kidney-health researcher at the University of California, San Francisco. This means your kidneys could be operating at reduced capacity for years before you notice any warning signs.

"So when the kidneys aren't working well, every cell and every organ in the body can be affected," says Dr. Jonathan Himmelfarb, a kidney specialist at Mount Sinai. The kidneys filter blood that circulates throughout your entire body, making their health crucial for overall wellbeing.

What Puts You at Risk for Kidney Problems?

Several factors can damage your kidneys over time, with some being more common than others. The most frequent culprits behind chronic kidney disease include well-known health conditions that many Americans already manage.

• Diabetes: High blood sugar levels can damage the tiny blood vessels in your kidneys over time
• High Blood Pressure: Uncontrolled hypertension puts extra strain on kidney blood vessels
• Cardiovascular Disease: Heart and blood vessel problems often go hand-in-hand with kidney issues
• Family History: Genetics and inherited kidney diseases increase your risk significantly
• Medication Overuse: Taking too many nonsteroidal anti-inflammatory drugs (NSAIDs) for extended periods can cause kidney damage

Other risk factors include infections, obesity, cancer, and certain medications. The key is catching and treating these underlying conditions as early as possible to reduce kidney damage.

Could New Blood Tests Catch Kidney Disease Earlier?

Traditional kidney function tests measure a substance called creatinine in your blood, but these results can vary greatly depending on your age, sex, physical activity levels, and other health conditions. "They're only an estimate of kidney function," Shlipak explains.

Researchers have been testing a more accurate approach using a second blood test for a substance called cystatin C. Unlike creatinine, cystatin C levels aren't as affected by personal differences. When doctors combine both blood tests, they can more accurately diagnose chronic kidney disease and detect it earlier, while also reducing the chances of misdiagnosis.

By the time symptoms do appear, kidney disease has often progressed significantly. Advanced signs can include swelling in your legs, feet, ankles, hands, or face, along with fatigue, loss of appetite, nausea, trouble concentrating, weight loss, shortness of breath, muscle cramps, or chest pain.

What Can You Do About Kidney Disease?

While chronic kidney disease can't be cured, early detection and treatment can slow its progression or even stop it from getting worse. "Dietary changes are a fundamental aspect of managing chronic kidney disease," says Dr. Meryl Waldman, who studies nutrition and kidney health at NIH.

People with CKD may need to limit foods high in sodium, potassium, and phosphorus, while those with advanced disease might also benefit from reducing protein intake. However, there's no one-size-fits-all meal plan—dietary advice depends on your disease stage, lab results, and other health conditions.

"Patients with CKD can feel like they're at the mercy of their illness. But dietary management can flip that script and help you become an active participant in your own health," Waldman explains. Medical nutrition therapy (MNT) can help personalize your diet for your specific needs.

The last decade has brought "remarkable advances in terms of medications that directly treat kidney disease," according to Shlipak. When someone receives an early or medium-stage diagnosis, doctors now have various options to slow disease progression. For people whose kidneys eventually stop working completely, dialysis—a treatment using machines to clean the blood—or kidney transplants may become necessary.

If you have risk factors for kidney disease, don't wait for symptoms to appear. Talk with your doctor about getting tested, and ask whether any medications you take could potentially damage your kidneys. The same lifestyle changes that help manage CKD—including exercise, adequate sleep, stress reduction, and avoiding alcohol and tobacco—can also help prevent it from developing in the first place.