Your kidneys may be small, but boy, are they crucial. Their job is to remove waste and excess fluid from your blood. They also control the amount of nutrients in your body such as sodium, potassium, phosphorous, and calcium: all key to keeping your vital functions going.
When your kidneys are in balance, they are a well-oiled machine. But other health conditions can cause them to veer off course, and, if they're left untreated, can ultimately progress to kidney failure, says Cassandra Kovach, MD, a nephrologist at the Cleveland Clinic. "The two main causes of chronic kidney disease are high blood pressure and diabetes, both of which are often preventable," she explains. (In the US, these two conditions are the causes of three out of four cases of kidney failure, according to the Centers for Disease Control and Prevention (CDC).
Here's a look at some of the most common causes of kidney disease and how you can protect against them.
causes of kidney disease , 3D Illustration Concept of Human Urinary System Kidneys Anatomy (NIDDK), and 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," explains Dr. Kovach. Eventually, your kidneys can become so damaged that they can no longer do the job they should.
What to do: if you have diabetes, you should have your urine checked at least once a year, to look for protein, says Dr. Kovach. You should also check your blood pressure regularly to make sure it's not elevated, as this also raises your chances to develop kidney disease. Be on the lookout for signs that your body is holding onto extra fluid (which can indicate early kidney disease) like weight gain, ankle swelling, and needing to use the bathroom more at night.
But it's also important to make sure that you have tight control of your diabetes. "Diabetes is one of the most modifiable risk factors," stresses David Goldfarb, MD, Clinical Chief of Nephrology at NYU Langone Health.
One study published in the Lancet in 2018, for instance, found that about half of people with type 2 diabetes who underwent an intensive weight-management program went into complete remission. While it's hard for most people to follow such a strict regime, just watching your diet and making sure you exercise most days of the week—even just brisk walking—can help. Your doctor will 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 NIDDK.
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High blood pressure
High blood pressure is the second leading cause of kidney failure in the US after diabetes, according to 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 work as well to remove wastes and extra fluid from your body. Extra fluid in the blood vessels may then raise blood pressure even more, creating a dangerous cycle, explains Dr. Goldfarb.
What to do: The best way to slow or prevent kidney disease from high blood pressure is to control it, stresses Dr. Kovach. If yours is high (and anything over 120/80 is now considered elevated, says the American Heart Association) get it under control pronto with lifestyle changes: make sure you are at a healthy weight, exercise, follow a heart healthy, low sodium diet like the Mediterranean diet, and don't smoke.
If you are diagnosed with kidney disease and already have high blood pressure, your doctor will take more aggressive steps to get it under control. The good news is, 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, says Dr. Goldfarb. It's not unusual for people with both conditions to require at least two drugs to control their blood pressure, he notes. Your doctor may also prescribe a diuretic, which is a medicine that helps your kidneys remove fluid from your blood, while also lowering your blood pressure as well.
This is the third most common cause of kidney disease, according to a 2021 review published by the US National Library of Medicine (NLM). It's an inflammation of your kidney's filters (otherwise known as glomeruli). There are two kinds: acute and chronic, says 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," explains 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, adds Dr. Greenwell. 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.
What to do: if you notice any of these symptoms after a bout with a bacterial infection like strep, see your doctor right away. "When it comes to acute glomerulonephritis, time is of the essence," stresses Dr. Greenwell. You may need to undergo temporary dialysis to help remove extra fluid and prevent kidney failure. If your symptoms are progressing very rapidly, your doctor may also order plasmapheresis, which filters your blood to remove harmful proteins, says the National Kidney Foundation.
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Polycystic kidney disease
This is a genetic disorder that causes cysts on your kidneys. Over time, these prevent your kidneys from doing their job of filtering waste products from your blood. It affects about 500,000 people in the US, or about 1 in 500 to 1,000 people. It usually doesn't develop until adulthood, says the NLM.
What to do: most of the time, you won't notice symptoms until kidney cysts are fairly 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," says 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 National Kidney Foundation. Other warning signs include:
- Back or side pain
- Blood in your urine
- High blood pressure
- Kidney stones
If you have a first-degree relative who was diagnosed with the disease—that means your mom or dad, a brother or sister, or your child—then you're also considered higher risk, and should talk to your doctor about genetic testing, per Mayo Clinic.
Treatment usually involves hypertension medication to lower high blood pressure and slow the progression of kidney disease, as well as a low-sodium diet, says Dr. Glassock. 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 US Food and Drug Administration.
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These can be things like kidney stones, or an enlarged prostate gland in men, says Dr. Kovach. "Sometimes, these can prevent urine from draining out of one of your kidneys, which causes your kidney to swell up," The main symptom is 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 actually becomes infected, notes Dr. Kovach.
What to do: your doctor will most likely start by checking your urine for blood or bacteria, to look for infection, as well as stone crystals to rule out kidney stones. They may also do blood tests to check your kidney function. If any of these tests are off, your doctor will 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, may mean medications and even possibly surgery. They 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," says Dr. Kovach.
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