The quiet warning signs your kidneys may be signaling

Kidney disease symptoms can creep up over time. Why a nephrologist says you need to pay attention now

July 15, 2026 5:00 AM

The Kidney Warning Signs You’re Missing— And Why Waiting is Dangerous

The Health Lab Live Show

Today, 30 million people in the United States have kidney disease, yet, as some data shows, only 20% know they even have the condition.

That’s alarming, since your kidneys are critical organs, says Julie Wright Nunes, M.D., a nephrologist at Michigan Medicine. Recently, she answers some basic questions about the humble kidneys.

Why are your kidneys important?

Kidneys are the two organs, each about the size of your own fist, located in your back flank area.

On a very basic level, they filter blood and remove waste through your urine.

But they do much more than that.

“The kidneys help regulate fluid balance, blood pressure and electrolytes like potassium and sodium. They help keep our bones healthy by working with vitamin D, calcium and phosphorus,” said Wright Nunes.

They also produce hormones that help your body make red blood cells and maintain healthy hemoglobin levels. In many ways, Wright Nunes explains, they help maintain the chemistry and balance that allows the rest of your organs to function properly.

“I like to think of the kidneys as the humble heroes of the body.”

Who’s at risk of developing kidney disease?

The two biggest risk factors for developing kidney disease include having diabetes and high blood pressure.

“Over time, both conditions can damage the kidney's filtering system,” said Wright Nunes.

Other important risk factors for chronic kidney disease include:

Being over 65

A family history of kidney disease

Having cardiovascular disease

Having autoimmune diseases

Certain genetic conditions, such as polycystic kidney disease

Certain medications and toxins

Some rare genetic conditions

What are the signs and symptoms of kidney disease?

One of the most important concepts is understanding the difference between signs and symptoms, says Wright Nunes, a professor of nephrology at the University of Michigan Medical School.

“Signs are things we can see, measure or observe like lab tests. Symptoms are things patients feel. The challenge with kidney disease is that it can be ‘quiet’ with respect to symptoms for a very long time. In fact, one of the biggest symptoms of kidney disease is often no symptoms at all.”

I like to think of the kidneys as the humble heroes of the body."
-Julie Wright Nunes, M.D., nephrology

You can actually have significant kidney disease while feeling completely normal, with ailments only creeping in over time, she notes, easily attributing them to a cold, or maybe just a viral infection you think you might have.

“Early signs we look for include changes in kidney function on blood tests, protein or albumin in the urine and high blood pressure. Symptoms that may develop later include swelling in the legs, fatigue, shortness of breath, a persistent cough with chest discomfort, nausea or vomiting, a metallic taste in your mouth, and in very advanced disease, confusion.”

That’s why, she says, screening is imperative.

“Kidney disease whispers before it shouts,” said Wright Nunes.

The dangers of ignoring your kidneys

What happens, though, if these early kidney disease signs are put off?

“Kidney injury can progress silently for years. And if not detected it can develop into irreversible scarring and reduced filtration called chronic kidney disease or CKD,” said Wright Nunes.

There are 5 stages of kidney disease:

Stage 1 - When kidney filtration is mildly reduced

Stage 2 -Similar to stage 1, but a little worse

Stage 3 - The kidneys start filtering at < 60%

Stage 4 – The filtering worsens at this phase

Stage 5 - Patients need a transplant or dialysis to survive.

The earlier we intervene, Wright Nunes notes, the more opportunities doctors and patients have to change their outcomes.

How to test for kidney disease

If you suspect an issue with your kidneys, speak up, says Wright Nunes.

“The good news is that kidney screening is simple,” she noted.

Two tests that provide excellent information include:

A blood test called eGFR, which estimates kidney function.

A urine test that looks for albumin or protein leakage

“These tests can identify kidney disease long before symptoms develop and tell us a lot about kidney health. There are a lot of other tests but that’s where a patient would work with a specialist [nephrologist] to decide which of these other tests, if any, are appropriate,” said Wright Nunes.

When bringing this up to your primary care provider, come prepared with questions prioritized to help advocate for yourself, says Wright Nunes, who also studies patient-doctor interactions and how to improve communication during clinical visits and outcomes.

Wright Nunes says keeping your blood pressure under control is key, usually to 130/80 or less, she notes.

Keep diabetes well managed if you have it, maintain a healthy weight, stay physically active, know the limits for your sodium intake, choose fresh foods whenever possible, avoid excessive NSAID medication use like Advil and stay well hydrated.

“Healthy habits don't replace medical care—but they amplify it in a positive way,” noted Wright Nunes.

Don’t wait to talk to your doctor

Although kidney disease is common and frequently under-recognized, it is important to feel empowered to bring up your concerns with your doctors.

“Know the two key tests to ask for: a blood test to know your kidney filtration, known as eGFR, and a simple urine test to test for urine albumin; ask your doctor if they have been done or will be done for you,” said Wright Nunes.

Even if kidney disease is often silent—or comes in quietly—it doesn't have to be an invisible condition that remains totally unknown, she says.

“Awareness and early action can completely change the trajectory, and if you have a diagnosis, it’s not the end of kidney health, it’s the beginning along a different and informed path for a healthy and fruitful life.”

Learn more about the nephrology division at Michigan Medicine.

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