The Sneaky Conditions That Can Harm Your Kidneys

by Sonya Collins Health Writer

Your kidneys are darn good at what they do. Every minute or so, they filter waste and water from a half-cup of blood and ferry the resulting urine over to the bladder. But they’re also delicate. So any condition that harms the blood vessels, especially diseases like diabetes and high blood pressure (HBP), can begin to interfere with their ability to function—which can lead to chronic kidney disease (CKD). Fortunately, there are steps you can take to control both conditions and reduce your odds of getting CKD—or slow its progression if you’ve already been diagnosed with it. Read on.

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What Is CKD, Anyway?

CKD simply means your kidneys are damaged (more on how, exactly, they get damaged in a moment), and they don’t filter blood the way they should. This damage happens slowly over time but can lead to the need for dialysis—when a machine filters and purifies your blood for you—or even a kidney transplant. A test called the Glomerular Filtration Rate (GFR) checks how well your kidneys are functioning by estimating how much blood passes through your kidney’s filters each minute. The results reveal how the disease progresses in five possible stages, from mild (stage 1) to severe (stage 5).

Silent Symptoms Make CKD Easy to Miss

CKD could develop for years before you notice symptoms. “It’s a silent disease, and the symptoms won’t be obvious to the patient,” says Anjay Rastogi, M.D., chief of nephrology at Ronald Reagan UCLA Medical Center in Los Angeles. But over time, you might experience morning nausea that lifts after you vomit. You may have loss of appetite, fatigue, weakness, sleep problems, decreased mental sharpness, and muscle twitches and cramps. You may also make more (or less) urine and develop swelling in your feet and ankles. A buildup of abnormal substances, including phosphorous, in your blood can cause itching.

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Diabetes Is the Top Cause of CKD

“Diabetes is the single-most important risk factor for the development of chronic kidney disease, and most patients who have CKD have diabetes,” says Jamie Dwyer, M.D., a nephrologist at Vanderbilt University Medical Center in Nashville, TN. About one in four adults with diabetes—types 1 or 2—also has CKD. “Long-term high blood sugar damages blood vessels and how they attach to the kidneys,” Dr. Dwyer explains. This damage occurs over many years and “it causes the kidney to leak protein from the blood into the urine.”

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How Diabetes Harms the Kidneys

Diabetes does additional damage to the kidneys by leaving scars—and these scars are what cause CKD. “There are roughly a million filtering units in a kidney,” says Dr. Dwyer. “As they scar, there is less healthy kidney tissue. That leads to progressive decline in kidney function.” Still, even if you have diabetes and CKD, it’s not written in stone that you’ll progress to the end stages of renal (kidney) disease. “Most of the time CKD shouldn’t lead to kidney failure,” says Dr. Rastogi. “Early diagnosis and management are both key.”

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High Blood Pressure Is the Second-Leading Cause of CKD

HBP is another big reason why 37 million U.S. adults have CKD, causing a quarter of all cases. Blood pressure is the force of blood against the inside of blood vessels as the heart pumps it out. When the force gets too high, the blood vessels expand to help the blood flow more easily. If you don’t control your BP, the constant pressure on the vessels damages and scars them—just as high blood sugar can. What’s more, people with diabetes usually develop HPB, because all that sugar damages the vessels—raising blood pressure. Yep, it’s a vicious cycle.

Other Risk Factors for Developing CKD

People who have both diabetes and HBP are at the highest risk for CKD. Other conditions and lifestyle factors that raise your risk include heart disease, smoking, obesity, family history of kidney disease, kidney abnormalities. Some research suggests being African-American, Native American, or Asian-American increases risk due to a combination of factors including higher rates of diabetes and obesity and lower rates of insurance coverage.

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Questions to Ask Your Doctor to Help Prevent CKD

Ask your doctor if you’re doing everything you can to stop or slow the progression of CKD. Prepare a list of questions before your next examination. “It’s only a 10 to 15-minute visit,” Dr. Rastogi says. “It helps to be organized.”

He suggests that you ask:

  • What is my blood-sugar goal? How can I reach it?
  • Do I need to lose weight? How much? How do I start?
  • What is the best diet for me?
  • Am I on the best medications to control my health conditions and prevent kidney damage?
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Managing Your Blood Pressure and Blood Sugar Is Essential

Tight control of your blood pressure and blood sugar is critical to reducing your risk of CKD. For many people that might mean medication. If that’s you, follow your doctor’s instructions to a T. Drugs could include ACE inhibitors, such as Capoten (captopril) and Vasotec (enalapril), which dilate blood vessels to increase blood flow, or ARBs, such as Avapro (irbesartan) and Cozaar (losartan), which keep blood vessels from tightening. For blood sugar control, drugs can include SGLT2 inhibitors like Farxiga (dapagliflozin) and Jardiance (empagliflozin). Some people with diabetes require insulin shots. Your doctor will decide what’s best for you.

Lifestyle Tweaks Have a Triple Benefit

Medication can be a lifesaver, for sure. And so can making a few simple changes to your lifestyle. The really good news? Everything you do along these lines will help you prevent all three conditions. And, it’s all the basics—things you probably already know! Exercise more, quit smoking, limit alcohol, and eat more plants. And, look, if you need improvement across the board, pick one area to focus on at a time.

Take Control to Live a Longer, Healthier Life

If you have diabetes or HBP, or both, the good news is that you don’t have to progress to CKD. And if you have kidney disease, that doesn’t mean that kidney failure is inevitable. Your everyday habits, including taking any medications your doctor prescribes and making the important lifestyle changes previously discussed have a lot to do with the progress of CKD—and the conditions that can lead to its development. “Even in the early stages of kidney disease, you can absolutely slow down the disease,” says Rastogi. “These are factors you can control.”

Sonya Collins
Meet Our Writer
Sonya Collins

Sonya Collins is an Atlanta-based independent journalist and editor. She covers health, medicine and scientific research, with a special emphasis on genetics and personalized medicine. Sonya is a regular contributor to WebMD Magazine, WebMD.com, CURE, and Staying Sharp. She is a contributing editor at The Conversation and WebMD.com.