Your kidneys and blood pressure are intertwined. Healthy blood pressure lets your kidneys function as they should, filtering waste products and keeping your fluid levels balanced. Likewise, healthy kidneys keep your blood pressure stable. If one isn’t working well, it can cause problems for the other.

For instance, having uncontrolled hypertension (high blood pressure) can damage your kidneys, causing the blood vessels in and around them to weaken. This reduces your kidneys’ ability to filter waste and can ultimately lead to chronic kidney disease.

Meanwhile, if your blood pressure is normal but your kidneys don’t work properly, this can cause high blood pressure — especially as your kidneys’ ability to filter waste worsens over time.

Here are nine more facts to know about how uncontrolled high blood pressure and kidney health are connected.

1. Uncontrolled Hypertension Damages the Kidneys

Uncontrolled hypertension can happen when someone has high blood pressure but doesn’t know it.

Uncontrolled hypertension can also occur when a diagnosed person’s medication does not control their blood pressure. When someone is taking multiple medications to control their blood pressure, and it’s still not working, it’s called resistant hypertension.

Regardless of the reason for your uncontrolled hypertension, it can damage your kidneys, especially if the condition persists.

For instance, high blood pressure causes your blood vessels to narrow and weaken, including those in your kidneys. When this happens, it impacts blood flow in and out of your kidneys and eventually makes it harder for them to do their job and filter waste from your body.

As kidney damage worsens, your kidneys may no longer work properly and can’t filter waste and extra fluids like they should. This can lead to kidney disease and make blood pressure harder to control.

2. Uncontrolled Hypertension Is the Second Leading Cause of Kidney Failure

Uncontrolled hypertension is the second leading cause of kidney failure in the U.S., after diabetes. In fact, high blood pressure is responsible for more than 25 percent of kidney failure cases. And, it’s becoming more of an issue.

For instance, the death rate of high blood pressure-related kidney disease has increased by nearly 50 percent in the U.S. over the last 25 years and has caused nearly 275,000 deaths from 1999 to 2023.

In addition to kidney failure, uncontrolled hypertension can also affect your heart health, leading to serious complications like heart attack, stroke, and heart failure.

3. A Vicious Cycle Exists Between Uncontrolled Hypertension and Kidney Disease

Your kidneys and your blood pressure influence one another. But when your blood pressure is uncontrolled, it can cause your kidneys to work harder and eventually damage them.

Likewise, if your kidneys aren’t functioning properly, this can lead to high blood pressure, because your kidneys cannot filter waste appropriately or help balance blood pressure. This creates a vicious cycle that allows uncontrolled hypertension to continue and kidney disease to worsen.

4. Protein May Leak Into Your Urine When You Have Uncontrolled Hypertension

If you have proteinuria (protein in your urine), your urine may look foamy or bubbly, or like the foam you might see if you scramble eggs. Consistently having these bubbles in your urine could be an indicator that your kidneys’ filtration system isn’t working properly.

Often, uncontrolled high blood pressure is the cause, though there are other possible explanations, too, like diabetes, dehydration, and rheumatoid arthritis.

If you have foamy urine, schedule an appointment with your healthcare provider.

5. Both Hypertension and Kidney Disease Are Asymptomatic in the Beginning

Most of the time, people with high blood pressure don’t have any symptoms. This may explain why 11 million of the 75 million people in the U.S. who have hypertension don’t know their blood pressure is too high and aren’t taking medications to control it.

Likewise, most people with kidney disease don’t experience noticeable symptoms. In fact, only 10 percent of people with kidney disease are aware of their condition. That’s why it’s so important to see a healthcare provider regularly.

Ask your doctor about your blood pressure readings, and be sure to discuss any risk factors for high blood pressure or kidney disease you may have.

6. Testing Is Available To See if Uncontrolled Hypertension Has Damaged Your Kidneys

If your healthcare provider suspects that your kidneys may be damaged, they may run several different tests. These include a blood test to check your estimated glomerular filtration rate (eGFR). This test shows how well your kidneys are doing and if they’re functioning properly.

Your healthcare provider may also perform a urine albumin-creatinine ratio (uACR) test. This test, which is recommended for people with high blood pressure, checks for protein in your urine.

Sometimes ultrasounds, CT scans, X-rays, or MRIs are also used to check your kidney health.

7. Blood Pressure Medications Can Slow the Progression of Kidney Disease

When you have high blood pressure, the medications included in your treatment plan for that condition may also help slow the progression of kidney disease. In fact, researchers indicate that commonly prescribed blood pressure medications may be the most useful in keeping kidney disease from getting worse.

8. Most Damage to Your Kidneys From Uncontrolled Hypertension Is Permanent

Once your kidney function has been affected by uncontrolled hypertension, there’s little that can be done to reverse the damage. In fact, most of the time, this damage is permanent.

That’s why knowing how high blood pressure can impact your kidneys is important. Not only can you take steps to prevent damage, but early detection also allows you to manage your condition and keep it from getting worse.

Talk to your doctor about your kidney health especially if you have uncontrolled high blood pressure.

9. Lifestyle Changes Can Improve Blood Pressure and Slow the Progression of Kidney Disease

While kidney damage cannot be reversed, there are things you can do to slow its progression. In addition to taking blood pressure medications and other recommended prescriptions, you can make lifestyle changes to promote kidney health and reduce blood pressure.

This includes reducing your salt intake and exercising regularly. Exercise can lower blood pressure, as well as improve blood sugar, boost mental health, and lower cholesterol.

Other helpful lifestyle changes include:

• Quitting smoking
• Maintaining a healthy weight
• Prioritizing sleep
• Managing stress

All of these things improve your quality of life and also slow disease progression.

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