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The Surprising Organ That Ages the Fastest-and What You Can Do About It

By Beth Ann Mayer Parade - Health Stories

Updated May 9, 2026 10:58 AM

Our bodies aren't machines, but sometimes, comparing them to one can help you take control of your health. One machine that many of us are very familiar with? A car. And a urologist wants us to think of our bodies like a car, at least for a moment.

"You wouldn't wait for the engine to start smoking to get an oil change, right? It's the same with your organs," states Dr. Mutahar Ahmed, MD, a urologist and the director of the Center for Bladder Cancer at Hackensack University Medical Center.

He shares it's vital to understand that your organs age just like the rest of you, and some get "older" faster than others, adding, "This knowledge is empowering because it puts you in the driver's seat of your own health."

The fact that your brain, heart, lungs, kidneys, liver, skin and other organs don't all celebrate the same birthday may surprise you. But a 2023 UK study of more than 5,500 people suggested that nearly 20% showed signs that at least one organ was on the fast track to aging. Unfortunately, quicker aging in an organ can increase the risk of death.

But it's not inevitable. A JAMA Pediatrics study suggested that having conditions or flags, like a psychological disorder, smoking or obesity, during adolescence was strongly linked to accelerated biological aging in midlife. Guess what these conditions have in common? They're treatable, meaning there's a lot you can do to slow aging down.

"Understanding this gives younger people a powerful reason to act early," explains Dr. David A. Taub, MD, the director of urologic oncology and robotic surgery at the Lynn Cancer Institute at Boca Raton Regional Hospital and Baptist Health South Florida, Boca Raton.

Understanding which parts of the body are at risk of rapid aging is a huge first step. To help, doctors share the surprising organ that ages the fastest and what you can do about it.

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The Surprising Organ That Ages the Fastest, According to Doctors

The kidneys can age more quickly than other organs, and that's an issue.

"The kidneys are the body's master filtration system, cleaning about 50 gallons of blood every day," Dr. Taub tells Parade. "They remove waste products and excess fluid, balance essential minerals like sodium and potassium, help regulate blood pressure, activate vitamin D for bone health, and produce hormones that stimulate red blood cell production."

The scientific community is still trying to pinpoint exactly why kidneys age more rapidly than other organs.

"We do not know why the kidneys age as quickly as they do," says Dr. Samir Parikh, MD, the chief of the division of nephrology at UT Southwestern. That said, he and his team recently published a study proposing a theory: It may be possible to detect kidney wear and tear by measuring damage to the battery powering various functions in our cells.

"These batteries are our mitochondria," Dr. Parikh says. "Mitochondria contain their own genetic code, and we think this wear and tear gets etched onto the mitochondrial DNA in a way that [damages] the functions of kidney cells."

It's one theory, and an attractive one because it offers hope of life-altering action. "It immediately suggests ways to measure wear and tear before it becomes a medical problem and potentially even intervene to repair the DNA code," Dr. Parikh shares.

Other doctors also point to the constant work kidneys do as a reason for the organ's rapid aging. Dr. Taub describes the kidneys as one of the "most metabolically active organs in the body." It takes a lot of energy to drive processes like filtration, reabsorption and secretion.

"Every day, the kidneys filter the entire blood supply dozens of times, exposing their delicate structures to toxins, fluctuations in blood pressure and oxidative stress," Dr. Taub says.

He adds that common conditions, like high blood pressure, high blood sugar and obesity can directly contribute to kidney damage. Dr. Ahmed agrees, saying that kidneys age more slowly in individuals without underlying conditions like type 2 diabetes and high blood pressure. Kidney aging happens faster when people have these conditions-and many do.

"Unlike some organs, the kidneys also have a limited ability to regenerate; once filtering units called nephrons are lost, they cannot be replaced," Dr. Taub adds.

What Happens in the Body as the Kidneys Age

All kidneys age. How quickly a kidney ages depends on your health and lifestyle.

"'Aging' in the kidneys means a gradual decline in their filtering capacity, and this can happen over time, not quickly," Dr. Ahmed says. "With age, the number of filtering units in the kidneys, called nephrons, naturally decreases, and the blood vessels that supply them can harden."

He adds that this decline makes the kidneys less efficient, sort of like a coffee filter that gets clogged over time, explaining, "It still works, but not as well as it used to."

As your kidneys stop filtering as effectively, Dr. Ahmed says waste products can begin to build up in the blood, contributing to health issues.

"Your body may hold on to excess fluid and salt, which can cause swelling and high blood pressure," he shares. "The balance of minerals in your blood can also be thrown off, which can affect other organs and systems in your body."

That said, the kidneys are going to age-because we age. "Starting around your 30s and 40s, kidney function may decline a little each year," Dr. Ahmed tells Parade. "The average drop is small-often about 1% per year or less in healthy people. Many people still have perfectly adequate kidney function into their 70s or 80s."

It can be hard to know where you stand, though. "Neither normal kidney aging nor actual kidney disease announce themselves to our bodies very often," Dr. Parikh says. "In fact, 9 out of 10 Americans diagnosed with kidney disease had no major symptoms before their diagnosis. The easiest way to know about your kidney health is to know your health numbers-your blood pressure, your blood sugar and whether your weight is too high for your frame."

If you're concerned, talk to your doctor. You may catch kidney decline early. As it progresses, Dr. Ahmed shares that the symptoms of kidney function decline may include:

Fatigue and trouble concentrating
Difficulty sleeping
Dry and itchy skin
More frequent urination, especially at night
Puffiness in your legs and ankles

What To Do About Kidney Aging

"The good news is that kidney aging, while inevitable to some degree, is significantly modifiable," Dr. Taub says.

In other words, you can make changes now to slow kidney aging. Below, kidney experts share their top three suggestions.

1. Control your blood pressure and blood sugar

Hypertension and diabetes are leading causes of kidney diseases. "Over time, they can damage the delicate blood vessels in your kidneys," Dr. Ahmed says. "Keeping these numbers in a healthy range is the single most important thing you can do for your kidneys."

2. Eat a balanced diet

Dr. Taub says diets like the Mediterranean or DASH diet are rich in fruits, vegetables, whole grains and legumes.

"[These] diets...reduce inflammation, lower blood pressure and decrease the production of waste products the kidneys must filter," he explains. "Keeping sodium below 2,300 mg per day helps protect the kidneys from the damaging effects of high blood pressure."

3. Stay hydrated

Staying hydrated can do quite a bit to support the kidneys. "Drinking enough water helps your kidneys clear sodium and toxins from your body," Dr. Ahmed says. "Think of it as helping to flush out the filters. Aim for around 1.5 to 2 liters a day, but this can vary based on your individual needs."

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Sources:

Dr. David A. Taub, MD, the director of urologic oncology and robotic surgery at the Lynn Cancer Institute at Boca Raton Regional Hospital and Baptist Health South Florida, Boca Raton
Dr. Mutahar Ahmed, MD, a urologist and the director of the Center for Bladder Cancer at Hackensack University Medical Center
Dr. Samir Parikh, MD, the chief of the division of nephrology at UT Southwestern
Organ aging signatures in the plasma proteome track health and disease. Nature.
Association of Treatable Health Conditions During Adolescence With Accelerated Aging at Midlife. JAMA Pediatrics.
Reversible compromise of physiological resilience by accumulation of heteroplasmic mtDNA mutations. Science.
Rate of decline in kidney function with age: a systematic review. BMJ Open.
Kidney Disease Statistics for the United States. National Institute on Diabetes and Digestive and Kidney Diseases.

This story was originally published May 9, 2026 at 10:50 AM.