Kidney Disease—5 Common Causes

Your kidneys may be small, but they are crucial. Their job is to remove waste and excess fluid from your blood, which are excreted as urine. They also control levels of key nutrients in your body, such as sodium, potassium, phosphorous, and calcium—all essential to keeping your vital functions going. Plus, they control blood pressure and keep bones healthy, says the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

When your kidneys are in balance, they are a well-oiled machine. But health conditions can cause them to veer off course, and, if the conditions are left untreated, they can ultimately progress to kidney failure, Cassandra Kovach, MD, a nephrologist at the Cleveland Clinic, said. "The two main causes of chronic kidney disease are high blood pressure and diabetes, both of which are often preventable," Dr. Kovach also said.

In addition, according to the Centers for Disease Control and Prevention (CDC), high blood pressure and diabetes are the cause of three out of four cases of kidney failure in the United States.

Here's a look at some of the most common causes of kidney disease and how you can work to manage these risk factors.

Type 1 or Type 2 Diabetes

Diabetes is the number one cause of kidney failure in the US, according to the NIDDK. About one-third of all adults with diabetes also have kidney disease.

"When you have too much glucose in your blood, over time it damages both the blood vessels and filters in your kidneys," Dr. Kovach said. Eventually, your kidneys can become so damaged that they can no longer do the job they should.

If you have diabetes, you should have your urine checked at least once a year, to look for protein, Dr. Kovach said. And it's also important to ensure that you have tight control of your diabetes. "Diabetes is one of the most modifiable risk factors," David Goldfarb, MD, Clinical Chief of Nephrology at NYU Langone Health, said.

One study published in The Lancet in 2018, found that about half of people with type 2 diabetes who underwent an intensive weight-management program went into complete remission. Remission in this study meant that their average blood glucose levels returned to normal without medications for diabetes.

It can be hard to follow such a strict weight-management regime. However, watching your diet and making sure you exercise most days of the week—even just brisk walking—can help.

Of course, reach out to your healthcare provider for guidance before beginning any new diet or exercise regimen. Healthcare providers can ensure any changes you make to your lifestyle are safe.

Your healthcare provider can also regularly check your A1C, which is a blood test that shows your average blood glucose level over the past three months. For most people, the goal is below 7%, per the NIDDK.

High Blood Pressure

High blood pressure is the second leading cause of kidney failure in the United States after diabetes, according to the NIDDK.

High blood pressure can damage blood vessels in the kidneys so they don't work as well. If the blood vessels in your kidneys are damaged, your kidneys may not adequately remove waste and extra fluid from your body. Extra fluid in the blood vessels may then raise blood pressure more, creating a dangerous cycle, Dr. Goldfarb said.

The best way to slow or prevent kidney disease from high blood pressure is to control your blood pressure, Dr. Kovach said. If yours is high (and anything over 120/80 is now considered elevated, according to the American Heart Association (AHA), you may be able to lower it with lifestyle changes.

Lifestyle changes promote well-being. They include striving to maintain a healthy weight, exercising, following an appropriate diet, and not smoking or quitting smoking if you already smoke.

The NIDDK described multiple steps to take to ensure a kidney healthy diet. These include:

• Consuming a diet lower in salt
• Eating a diet that contains the right proteins and the right amount (typically smaller portions of protein to reduce strain on your kidneys)
• Eating heart-healthy foods (think foods that are grilled or roasted instead of fried, and limit trans and saturated fats)
• Choosing foods and drinks with less phosphorous (meats, dairy, beans, and nuts are all examples of higher phosphorous foods)
• Ensuring you are selecting foods and drinks with the appropriate amount of potassium

If you are diagnosed with kidney disease and already have high blood pressure, your healthcare provider may prescribe medications to help control it. The good news is that two types of blood pressure-lowering meds—angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs)—work well to both lower your blood pressure and slow the progression of kidney disease, Dr. Goldfarb said.

Dr. Goldfarb also said it's not unusual for people with both conditions to require at least two drugs to control their blood pressure.

Your healthcare provider may also prescribe a diuretic. Diuretics help your kidneys eliminate fluid and sodium from your body, explains StatPearls. The decrease in fluids from diuretics also helps to lower blood pressure because, with less fluid, there is less blood volume for the heart to pump.

Glomerulonephritis

Glomerulonephritis is another cause of kidney disease, according to StatPearls. It's an inflammation of your kidney's filters (otherwise known as glomeruli).

There are two kinds: acute and chronic, per the National Kidney Foundation (NKF). "Acute can come after a bacterial infection like strep throat, or even be triggered by an autoimmune disease such as lupus," said Robert Greenwell, MD, chief of nephrology at Mercy Medical Center in Baltimore. Signs include:

• Swelling in your face, especially in the morning
• Blood in your urine
• Peeing less than usual

Chronic glomerulonephritis is a little different. It may be genetic, or it can also be caused by an autoimmune disease, Dr. Greenwell said. You can also develop chronic glomerulonephritis years after you experience an acute attack. These symptoms are similar to the regular signs of kidney failure, like protein in your urine, swelling in your ankles, and going to the bathroom a lot at night.

If you notice any of these symptoms after a bout with a bacterial infection like strep, see your healthcare provider right away.

"When it comes to acute glomerulonephritis, time is of the essence," Dr. Greenwell said. You may need to undergo temporary dialysis to help remove extra fluid and prevent kidney failure. If your symptoms are progressing rapidly, your healthcare provider may also order plasmapheresis, which filters your blood to remove harmful proteins, per the NKF.

Polycystic Kidney Disease

Per MedlinePlus, this is a genetic disorder that causes cysts on your kidneys. Over time, these cysts prevent your kidneys from doing their job of filtering waste products from your blood. Polycystic kidney disease affects about 500,000 people in the United States or about 1 in 500 to 1,000 people. Additionally, it usually doesn't develop until adulthood.

Most of the time, you won't notice symptoms until kidney cysts are relatively large—at least a half inch in size. "By then, they're so large that you feel quite bloated and uncomfortable, and you may even notice that you have a loss of appetite because your kidney is pressing up against your digestive organs," Richard Glassock, MD, professor emeritus at the David Geffen School of Medicine at UCLA and past president of both the American Society of Nephrology and the NKF, said.

Other warning signs include:

• Back or side pain
• Blood in your urine
• Headaches
• High blood pressure
• Kidney stones

Per MedlinePlus, approximately 90% of individuals with this condition inherited it from their parents. MedlinePlus also explained about 10% of individuals develop polycystic kidney disease without any known family history, but this is far rarer. If you are concerned about your family's history with the condition, your healthcare provider can help determine if genetic testing or further diagnostics are necessary.

Treatment for polycystic kidney disease usually involves blood pressure medication to lower high blood pressure and slow the progression of kidney disease, as well as a low-sodium diet, Dr. Glassock said. Your doctor may also prescribe tolvaptan, a type of drug known as a vasopressin receptor antagonist that slows down the rate of the disease, per the U.S. Food and Drug Administration (FDA).

Kidney Obstructions

These can be things like kidney stones, or an enlarged prostate gland in males, Dr. Kovach said. "Sometimes, these can prevent urine from draining out of one of your kidneys, which causes your kidney to swell up."

The main symptom is a pain in your side or back, known as flank pain. But you may notice pain when you pee, and feel the urge to go more frequently. Sometimes, you can also have nausea and fever, if the backed-up urine causes an infection, Dr. Kovach said.

Healthcare providers will most likely start by checking your urine for blood or bacteria to look for infection and will want to rule out kidney stone. They may also do blood tests to check your kidney function. If any of these tests are off, your healthcare provider may also do a kidney ultrasound.

The treatment is usually to treat the underlying cause—if it's an infection, that means antibiotics, and if you have kidney stones, treatment may mean medications and possibly surgery. The healthcare team may also drain the trapped urine from your bladder via a catheter. "The key is to get it addressed as soon as possible, to avoid any permanent kidney damage," Dr. Kovach said.

A Quick Review

If kidney disease is something you are concerned about, there are a few things you can do at home to monitor for the condition and keep your kidneys healthy. For example, you can check your blood pressure to make sure it's not elevated, since high blood pressure increases the risk of developing kidney disease.

You can also be on the lookout for signs that your body is holding onto extra fluid (which can indicate early kidney disease). These signs include weight gain, ankle swelling, and needing to use the bathroom more at night.

And, if in doubt, or if you are concerned about your health, your healthcare provider is a great resource for the next steps.