The bad news about her kidneys came when she switched to a new doctor closer to her home for Gail Rae-Garwood, now in her late 60s.
“She decided that as a new patient, I should have all new tests,” says the Glendale, Arizona, resident.
“When the results came in, she got me an appointment with a nephrologist the next day. When you get an appointment with a specialist the next day, you know something is not right.”
Rae-Garwood had chronic kidney disease. “My GFR was down to 39, and apparently had been low for quite a while,” she says. (Your GFR, or glomerular filtration rate, is the rate at which your kidneys filter your blood.)
“‘What is chronic kidney disease and how did I get it?’ I demanded,” Rae-Garwood recalls.
Every 30 minutes, your two kidneys filter all the blood in your body. Without at least one, you need dialysis or a transplant.
Yet most people have no idea how well their kidneys are working.
“It’s very common for people to have no idea that they have early chronic kidney disease,” says Alex Chang, a nephrologist at Geisinger Health System in Danville, Pennsylvania.
Your glomerular filtration rate
A routine blood test sent to a major lab—like Quest or LabCorp—typically includes your GFR. If it doesn’t, your doctor can calculate it.
“A GFR is pretty routine for anyone who has blood work done,” says Chang. “But if you have very mild kidney disease, and especially if you’re older, a doctor might not mention it since kidney function tends to decline as you age.”
Doctors also look for kidney disease by testing your urine for a protein called albumin. “That’s usually only done if you have high blood pressure or diabetes or some risk factor for kidney disease other than age,” says Chang.
Rae-Garwood’s previous doctor missed that memo. “I had been on medication for high blood pressure for decades,” she explains. “I wonder how much more of my kidney function I could have preserved if I’d known about it earlier.”
Millions of people have the biggest risk factors for kidney disease
Age. “Age is a very good predictor of risk,” notes Geoffrey Block, associate clinical professor in medicine at the University of Colorado Health Sciences Center. “There’s no stronger risk factor for kidney disease.”
A normal GFR is 90 or above, but some doctors consider 60 or above normal for older people.
“There’s some debate about whether a small decline in kidney function is just part of normal aging or if it’s really a pathologic loss of kidney function,” says Block.
Diabetes. “Diabetes is the second biggest risk factor,” says Block, not only for getting kidney disease but for its consequences—heart attacks, strokes, heart failure, and further kidney damage.
One in three adults with diabetes have chronic kidney disease. And people with diabetes make up nearly 44 percent of new cases of kidney failure. That’s when you need dialysis or a kidney transplant to survive.
And it’s not just diabetes. “Some studies show that prediabetes can increase the risk of kidney damage later,” says Chang.
Hypertension. One in five adults with high blood pressure also have chronic kidney disease.
Race. “We know that African-Americans are more at risk for developing kidney disease and more at risk to have their kidney disease progress,” says Block.
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