SPEAKERS
Tiffany, Dr. Grandhi
00:02
DNA’s podcast series, Let’s Talk About Kidneys, provides education dedicated to exploring the journey of those living with chronic kidney disease. We’re here to inspire meaningful conversations and to help people living with CKD gain a better understanding of their disease.
Tiffany 00:25
Kidney stones are very common, affecting approximately one in five males and one in 10 females by the age of 70. Today, we will discuss what kidney stones are, what causes them, and how they can be prevented and treated.
Dr. Jaya Grandhi joined Dallas Nephrology Associates in 2020. Dr. Grandhi is board certified in internal medicine and nephrology and is also the director of DNA’s Polycystic Kidney Disease Center of Excellence program. She currently sees patients at our Irving and Las Colinas office locations. She helps patients with various kidney disorders, including kidney stones, polycystic kidney disease, chronic kidney disease, uncontrolled hypertension, protein in the urine, and electrolyte issues, among other problems.
Welcome to the Let’s Talk About Kidneys podcast. Dr. Grandhi, can you kick off the podcast and first give us the baseline understanding of what kidney stones are?
Dr. Grandhi 01:25
Thank you so much for having me, Tiffany.
Kidney stones, also called nephrolithiasis, as the name implies, are basically small stones that form in the kidneys. These stones are usually composed of salts and minerals that are normally present in the urine, but sometimes they clump together, crystallize, and over a period of time develop into kidney stones. They’re usually seen when the urine is very concentrated.
They’re extremely painful to pass, so once you have a kidney stone, nobody wants to have a kidney stone again. But we do have measures that we can take so that people don’t develop kidney stones in the future.
And so, what are the different types of kidney stones? Yes, there are two main types of kidney stones. They are calcium-based stones and non-calcium-based stones.
Calcium-based stones come in two variants. The most common type of kidney stone is a calcium oxalate stone. In this, both the calcium and the oxalate combine together in the urine. Usually, they form in acidic urine, crystallize, and form kidney stones.
People who are not drinking enough water have concentrated urine. They have too much calcium and oxalate in their urine, and that results in the formation of calcium oxalate stones.
Calcium phosphate stones happen more commonly in alkaline urine. The calcium and phosphorus combine together and form calcium phosphate stones. Similar to calcium oxalate stones, these patients also have high calcium and phosphorus in their urine, but they tend to have alkaline urine.
Coming to non-calcium-based stones, the most common is uric acid stones. It has become very prevalent now because of the increase in people being overweight and obese and having issues with insulin resistance. All of these cause acidic urine. There is a high production of uric acid in the urine that causes the uric acid to crystallize, resulting in the formation of uric acid stones.
The two less common types are struvite stones, which form in alkaline urine and are associated with recurrent urinary tract infections. There is a rare form called cystine stones, which is a genetic condition. It tends to run in families.
It is super important to know what type of kidney stone you are forming because the causes can be quite different, and prevention depends upon what kind of kidney stone you are having.
Tiffany 04:10
Okay, and so can you give us a couple of examples of what causes kidney stones?
Dr. Grandhi 04:18
Yes. As we discussed, kidney stones happen because of an imbalance between the fluid and the various salts and minerals in the urine. If people are not drinking enough water, they form very concentrated urine that puts them at a high risk of having kidney stones.
If you have somebody in your family who has had a kidney stone, like a mom, brother, or child, you’re at a high risk of having kidney stones.
Certain lifestyle behaviors are associated with kidney stones. If you eat too much salt in your diet, the kidneys have to filter the salt into the urine, and salt drags calcium along with it. As we discussed, calcium-based stones are the most common type of stones.
If you eat too much animal protein in your diet that causes acidic urine that can increase the risk of formation of both calcium oxalate and uric acid stones.
If you take too many over-the-counter supplements, things like high doses of vitamin C and curcumin, they get converted to oxalate, and that can increase the risk of formation of kidney stones.
If you are taking a lot of antacids for acid reflux or heartburn, that can increase the risk of formation of calcium-based kidney stones.
So it’s a combination. I would say it could be because of genetic reasons or because of lifestyle behaviors. Sometimes you could have underlying medical conditions that predispose you to kidney stones.
Things like hyperparathyroidism. We have four glands in the neck called parathyroid glands. They’re adjacent to our thyroid gland and regulate the calcium and phosphorus balance in the body. Sometimes one of the glands starts overacting and starts releasing too much calcium from the bones. The kidneys have to filter this calcium into the urine, which puts you at risk of having kidney stones.
Conditions like gout cause high levels of uric acid in the bloodstream, and that can lead to both gout and kidney stones.
Things like obesity, type 2 diabetes, and prediabetes with insulin resistance tend to cause uric acid stones.
Inflammatory bowel disease, like Crohn’s disease and ulcerative colitis, can also increase the risk. Because of multiple diarrheal episodes, patients lose a lot of fluid in their stool, leading to very concentrated urine, and that can result in kidney stones.
Tiffany 07:02
Okay, so can you describe what are some of the symptoms that someone should look for to see if it’s an indicator that they have a kidney stone or one that’s forming?
Dr. Grandhi 07:13
Yeah, absolutely. Sometimes kidney stones can be completely asymptomatic. They are found incidentally when patients undergo an ultrasound of the abdomen or a CT scan for some other reason.
Sometimes patients can present with what we call renal colic. Here, patients come in with severe pain in their flank, that is the area right in the back below your rib cage.
Tiffany 07:40
Does it matter which side, or does it happen on both sides?
Dr. Grandhi 07:44
It depends on which side the stone is passing through the ureter. That’s what causes the renal colic. So the pain starts in the flank and goes into your lower abdomen or into the groin.
This usually happens because there is a tiny tube that connects the kidney to the bladder called the ureter. When the stone is passing through the ureter, it causes ureteral spasm. That’s why patients experience severe pain.
This can be associated with increased frequency of urination, urinary urgency, sometimes blood in the urine, nausea, and vomiting. So there are two ways of presenting. Either they can be seen as an incidental finding, or patients can present with classic renal colic.
Tiffany 08:28
Okay, classic renal colic. All right. So how are kidney stones actually diagnosed?
Dr. Grandhi 08:37
Yes. So when a patient comes to our clinic with a kidney stone, we go through their history and determine what kind of medical conditions they have that may predispose them to kidney stones.
It’s super important to know their dietary history. How much water are they drinking? Are they following a low-salt diet, or are they eating too much salt? Are they eating too much animal protein? Are they taking any supplements that could predispose them to form kidney stones?
We do some blood work to check their kidney function and a few other things like calcium levels and uric acid levels in the bloodstream.
The most important test once a patient forms a kidney stone is a 24-hour urine collection. This gives us a lot of information about how much urine volume they are producing and the concentration of various salts in the urine.
We look at their urine calcium level, oxalate level, uric acid level, phosphorus level, citrate level, and urine pH.
As we discussed, certain types of kidney stones, like calcium oxalate and uric acid stones, are more common in acidic urine, and calcium phosphate stones are more common in alkaline urine.
Coming to imaging, we usually do a CT scan of the abdomen to see how many kidney stones they have and how big they are.
Tiffany 09:59
So people can have multiple kidney stones?
Dr. Grandhi 10:00
Absolutely.
Tiffany 10:03
Oh, I know that’s painful.
Dr. Grandhi 10:04
Very painful. Usually pain happens when they’re actually passing the kidney stone. Sometimes they can be there and not cause many symptoms. As I said, they may just be diagnosed incidentally.
The CT scan gives us the number of kidney stones and the size of the stones because we need to determine if they require procedures to remove them. It also shows us if any of these stones are causing obstruction to the kidneys.
Tiffany 10:33
So for individuals that are either watching or listening, what can they do to prevent kidney stones?
Dr. Grandhi 10:42
Super important. There are general measures and there are specific recommendations depending on the type of kidney stone.
General measures start with increasing water intake. Number one, hydration, hydration.
Tiffany 10:58
So when you say increase water intake, what would be the minimum ounces per day? I know people walk around with their water jugs with the ounces listed, so what would be a good minimum amount to help with prevention?
Dr. Grandhi 11:16
Yes. I recommend people have at least 100 ounces, or three liters, of water on an everyday basis because we want a urine output over two and a half liters per day. Water helps dilute these minerals and salts and reduces the risk of kidney stone formation.
It is hard for people to increase water intake in the beginning, but it becomes a habit. You just have to keep doing it.
I always tell patients to buy one of those one-liter water bottles so they can fill it up three times and know that they have had enough water.
One of the telltale signs you can look for is whether your urine is clear or just light yellow in color. That means you are drinking enough water.
Some patients tell me, “Doctor, I don’t like water. What am I supposed to do?” So I recommend adding flavoring agents like Crystal Light, or adding cucumber slices, lemon slices, or orange slices to the water just to give it some flavor.
And drink water. What’s the side effect? You’re going to urinate a lot because you’re drinking all this water, but you have to understand that you don’t want to have a kidney stone again.
Tiffany 12:35
It’s better to urinate often than to have a kidney stone again. You have to choose your battles.
Dr. Grandhi 12:44
Yes, exactly.
Dr. Grandhi 12:45
Another important thing is lowering the salt intake in your diet. A lot of processed meals have a lot of salt, right? Once you start looking at nutrition labels and keeping track of your salt intake, it’s unbelievable how much salt is present in processed meals.
The second thing is eating out at restaurants and getting takeout multiple times a week. That’s not good for general health and not good for kidney stones. Start taking food from home. Cut back on eating outside.
A third general recommendation would be to reduce your animal protein intake, like red meat, chicken, and seafood.
I recommend my patients try a plant-based diet. Go meatless on Mondays. Start off with one day per week and then maybe go up to two days a week or so. It’s not hard. It’s just a change in how you’re eating.
Tiffany 13:42
Right, and it’s a necessary change.
Dr. Grandhi 13:46
Exactly. Be very careful about over-the-counter supplements. Don’t take calcium tablets and things like that.
But a super important point is, don’t restrict calcium in your diet. When you restrict calcium in your diet, you actually end up forming more kidney stones.
The reason is that the calcium in your foods binds to oxalate and helps get rid of it in the stool. So it actually reduces the risk of forming calcium oxalate stones. But don’t take supplements.
Coming to specific recommendations for different types of kidney stones, for calcium-based stones, in addition to increasing water intake and lowering salt intake, we use medicines called thiazides.
Tiffany 14:37
These are actually blood pressure medications, and so these are part of treatment, correct?
Dr. Grandhi 14:43
Yeah. The thiazide diuretics, one of the side effects of these medicines is that they lower the calcium in the urine. So we use that to our advantage in our kidney stone patients. They reduce calcium excretion in the urine and lower the risk of calcium-based kidney stones.
For people who are forming more uric acid stones, we ask them to reduce their animal protein intake in addition to increasing water intake and reducing salt intake.
We use medications like allopurinol, which reduces the production of uric acid by the body so that the uric acid in the urine goes down.
As we know, uric acid stones tend to form more in acidic urine. We use medications like potassium citrate and sodium bicarbonate, which help alkalinize the urine and reduce the risk of uric acid stone formation.
Tiffany 15:46
So Dr. Grandhi, can you tell us how kidney stones are actually treated?
Dr. Grandhi 15:52
Yes. If a patient is coming in with acute renal colic, remember the pain that they were having in their flanks going into their groin, but they are otherwise stable and are able to eat and drink, we use pain medications to control the pain, give them nausea medicine, and use a medication called tamsulosin to help them pass the stone.
But if a patient presents with severe flank pain and they’re not able to keep anything down because of nausea and vomiting, we ask them to come to the emergency room so that we can place an IV line, give IV pain medications, fluids, and tamsulosin so they can pass the stone.
If they are having a very high fever along with pain, I always recommend they come to the ER because there is probably an infection and an obstruction that has predisposed them to the infection.
They need to immediately be seen by a urologist to remove the stone, and they need IV antibiotics.
If they are coming in because they have multiple stones but they’re not in pain right now, then it depends on the size of the stones.
If they are less than five millimeters, usually patients are able to pass the stone themselves by increasing their water intake and reducing their salt intake. If they are acutely passing the stone, we give them tamsulosin to help with passage.
If the stones are between five and 10 millimeters in size and are located closer to the kidney rather than the bladder, they usually end up needing a procedure to remove the stone. That’s when we refer them to our urology colleagues.
If they are over 10 millimeters in size, it is very unlikely that they will pass the stone. We refer them to our urology colleagues to perform procedures to remove them.
Our urology colleagues can do procedures like shock wave lithotripsy, where they use sound waves to break the stones so that patients are able to pass them.
Sometimes they perform ureteroscopy, where they place a camera into the bladder and then go up along the ureter to remove the stone or break it apart so the patient can pass it.
Sometimes they perform a procedure called percutaneous nephrolithotomy. This is used for large stones over 20 millimeters, where they use a tool to directly access the kidney and remove the stone through an incision.
Tiffany 18:41
Can you give us an example of maybe a patient that you’ve treated with kidney stones, whichever type?
Dr. Grandhi 18:48
Yeah, absolutely. So I had this 45-year-old gentleman who came to my office referred by his primary care physician because he was forming kidney stones almost every two to three months.
Tiffany 18:59
Yeah.
Dr. Grandhi 19:01
He brought me a stone for analysis, and it turned out to be both a calcium oxalate and a uric acid stone, so he had both.
On further questioning, he told me he was training for a marathon and thought he was drinking enough water. But when you’re training for a marathon or working in hot weather conditions, you tend to lose a lot of salt and water through your body, so your urine can become very concentrated.
When we did a 24-hour urine collection, we found that he was eating a lot of salt in his diet. His urine output was around 1,500 milliliters, and we usually aim for over 2,500 milliliters because he was losing a lot of fluid through sweat.
His urine calcium was very high. His urine pH was low, meaning he had acidic urine, and his uric acid was super high because he was eating a lot of animal protein while training.
Tiffany 19:57
Yeah, yeah.
Dr. Grandhi 19:58
So we worked with him to increase his water intake. He cut back tremendously on his salt intake. He stopped eating out at restaurants and getting takeout and started eating more meals at home.
He reduced his animal protein intake and started incorporating more plant-based foods into his diet.
I had to put him on a couple of medications, including the thiazide diuretics that I discussed with you earlier to reduce the calcium in the urine, and also potassium citrate to alkalinize the urine and increase the solubility of uric acid.
And he’s doing wonderful. He’s been stone-free for the last two years.
Tiffany 20:45
Oh, that’s awesome. Dr. Grandhi, this has been so informative and such an awesome topic to discuss. We thank you so much for your participation and being here with us today. Did you enjoy your time?
Dr. Grandhi 20:59
Absolutely, absolutely. Thank you so much for having me on this podcast. I loved it.
Tiffany 21:05
Awesome. Thank you.
Thank you, Dr. Grandhi, for your participation today and for improving our patients’ and their families’ understanding of kidney stones.
Please keep in mind that people can develop kidney stones even if they do not have kidney disease. If you have kidney stones, your doctor will create a treatment plan that may include changes to your diet and medications to help lower your risk of forming more stones.
There are many treatment options available, including general advice and specific recommendations based on the type of stone that you have.
We hope you found this podcast helpful and informative. Thank you for joining us today.
To learn more, call 214-358-2300 to schedule a consultation.
Thank you for joining us today. For information about Dallas Nephrology Associates, please visit our website at DNEPH.com.
If you found our information helpful, feel free to share it with others who may also be affected by chronic kidney disease.