>>Welcome to the ABCs of Kidney Disease. I’m Daphne Knicely, and today I’m gonna talk to you about the causes and stages of
chronic kidney disease. This video is a part of the
Johns Hopkins Nephrology Patient Education Program, and we’d like to thank our sponsors, The Ed Kraus Endowment
and the Shah Foundation. So chronic kidney disease is a silent problem in the United States. There are 30 million people
in the United States alone that have kidney disease. That’s about one in seven people. And the crazy fact about
this is 97% of them have absolutely no idea
they have kidney disease. That’s because most of the
time kidney disease is silent. There is no symptoms until
you’ve basically lost 90% of your kidney function, and you’re getting close
to needing dialysis. Now a lot of people are at
risk for kidney disease. One in three patients
with diabetes is at risk. One in five with high
blood pressure is at risk. Also those that are over the age of 60, that are obese, have
cardiovascular disease, or certain ethnic groups are
at risk for kidney disease. So how do we screen or
diagnose for kidney disease? Well, there are two tests that I use. So, one is a urine test. It’s a urinalysis or urine dipstick, and really what I’m looking for is blood or protein in the urine. You should not have blood
or protein in your urine. They’re actually really big molecules. So the example I like to use. It’s like pasta falling
through a strainer. It shouldn’t happen. Or for the kidney, it tells me that there’s
damage to the kidney’s filter that’s allowing protein or
blood to fall in the urine which should not happen. And sometimes people will have… This is their first sign of kidney disease before they have any chemistry changes. The next test I use is
the blood creatinine test. So creatinine comes from muscle. It’s just a normal waste product, but you only get rid of
it through your kidneys. So when it goes up in the blood I know the kidneys
aren’t working perfectly. But it’s not a perfect test. It I have a 90-year-old woman
that maybe weighs 90 pounds, and I have a big
body-builder, a 20-year-old, who weighs like 300
pounds of solid muscle, they have different muscle amounts, and so they’re generating
creatinine at a different rate. But maybe they both have a creatinine in their blood test of
one, which is normal. But what it tells me is that body-builder is working overtime to
get rid of creatinine. His kidneys are perfect. Whereas that 90-year-old woman, her kidneys might not be working
as perfect as they used to, ’cause really she has no muscle mass and her creatinine probably should be 0.5. But instead of me guessing this, we have something called a
Glomerular Filtration Rate, and it’s really a calculation where we take into account your
age, your race, your gender, and your creatinine level. And so what happens is if your creatinine goes up in the blood, I think your kidneys aren’t working great. Well, the Glomerular Filtration
Rate works the opposite way. It decreases when your
kidneys aren’t working great. So they move in opposite directions. So what really is this
Glomerular Filtration Rate? Well, it’s literally a measure of how many milliliters per minute of blood your kidney’s filtering. But, for me, it tells me how much function of your kidney that you have. So normal is about 90 to 100, and it decreases as they
kidney ages over time and as the kidney disease gets worse. And I use this Glomerular Filtration Rate to stage kidney disease. So what are the stages of kidney disease? So there are five, and the first stage is when
that Glomerular Filtration Rate is more than 90. But maybe I know that
there’s damage to the kidney. Maybe I have a kidney biopsy. Maybe I have blood or
protein in the urine. Then stage two is from 60 to 90, stage three is from 30 to 60, stage four is from 15 to 30, and stage five is less than 15. Usually as a kidney doctor, I don’t start seeing patients till around stage three, four, or five. And most of the time if
somebody’s in stage four, that’s when I start the
discussion with them about well in the future if
your kidneys got worse, are you thinking about
dialysis or a transplant, and I talk to them about the options. We don’t start it then, but
we start talking about it. And then in stage five,
really it’s not until that Glomerular Filtration
Rate is about five to 10 before people start to develop
symptoms of kidney disease. And that’s when they usually
need to start dialysis. So I use the stages of
kidney disease a lot as a kidney doctor. One, it tells me how
well your kidney disease, if it’s progressing or not, and two, it tells me how
often do I need to get labs and how often I need to see you in clinic. ‘Cause somebody in stage
two compared to stage four, I’m not gonna see someone
in stage two that often, maybe once or twice a year, whereas somebody in stage four I might see every three
months or every two months. It depends on how their
kidney function is trending. There are a lot of different causes for chronic kidney disease, but the number one in the United States and in any developed country is diabetes. Diabetes can affect any organ in the body, and it’s known to affect the
kidneys if it’s not controlled. High blood pressure is
the number two cause for chronic kidney disease in the U.S. And then after that it’s
kind of a mixture of things. So there’s a category
called glomerulonephritides or glomerulonephritis, and really this is a group of diseases where your body’s attacking your kidneys. You’re making some sort of antibody maybe due to things like
lupus or something else, or you have a disease
specific to your kidney like IgA nephropathy or
membranous nephropathy. Some other causes. There’s inherited diseases. So a good example of this would be like polycystic kidney disease where your entire kidney
gets replaced by cysts. Then we have some other diseases. So like urinary tract obstructions. So most common is for men
having prostate problems. Well, like I explained in
one of our other videos, is from going from your
bladder out of the body is your urethra, and for men, that goes through your prostate. So if your prostate enlarges it basically pinches off that tube and you can’t get rid of urine. Well that backs up to the
kidneys and causes damage. For women, this could be uterine fibroids that can cause obstruction or blockage. Also repeated kidney infections can cause damage to the kidney. So I have a actual infection of my kidney, that can cause scarring over time. And then sometimes we have medications. Every medication has side effects, and sometimes medications are necessary, but sometimes those medications can cause damage to our kidneys. If you’re interested in learning more about chronic kidney
disease, causes and stages, then check out our resources. Also if you wanna know about
normal kidney function, the complications of kidney disease, or treatment of kidney failure,
check out our other videos.