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112: Just How Painful is a Kidney Stone?

Aug 16, 2022

Did you know a kidney stone is more painful than childbirth and the amputation of a finger? Troy has seen the pain first hand in the ER. Urologist John Smith, MD, is back to explain what causes kidney stones, how they’re treated and - most importantly - four ways to prevent a stone from forming.

Episode Transcript

This content was originally created for audio. Some elements such as tone, sound effects, and music can be hard to translate to text. As such, the following is a summary of the episode and has been edited for clarity. For the full experience, we encourage you to subscribe and listen— it's more fun that way.

Scot: They say kidney stones are more painful than childbirth, if you can believe that. I suppose people who have had kidney stones would think that. This is "Who Cares About Men's Health," a Men's Health Essentials. We're talking about kidney stones today. Is there anything you can do to prevent them?

And we've got the cast and crew here today. My name is Scot Singpiel. I bring the BS. We've got Dr. Troy Madsen. He is the MD to my BS.

Troy: Hey, Scot. I've never given birth to a child, but I imagine it's painful and I imagine kidney stones are much more painful.

Scot: Producer Mitch is also on the show.

Mitch: Hey. So I'm looking at this pain scale, not to derail too far, but out of 50, a kidney stone says it's 42, and childbirth is a 32, and a really bad tooth break is a 19.

Scot: Oh, wow.

Mitch: I'm excited to hear more.

Scot: Dr. John Smith is a urologist. He's going to help sort us through the kidney stones. How are you doing today?

Dr. Smith: Oh, living the dream, gentlemen. Thanks for having me.

Scot: You ever have kidney stones?

Dr. Smith: I have not, but I've seen enough patients that have that I drink four liters of water a day to make sure I don't have one.

Scot: It's one of those things where when you see somebody that has it, you start doing the things that are going to prevent you from getting them. Is that actually one of the good things to do? Is it caused by not drinking enough water, or can you prevent them by drinking more water?

Dr. Smith: Absolutely. So the old Chinese proverb of the solution to pollution is dilution is correct.

Mitch: I love that.

Scot: Is that a Chinese proverb?

Dr. Smith: I don't know. It was told to me when I was training by one of my mentors and he said it was a Chinese proverb, but it doesn't sound like one to me. It just sounds like good advice.

Scot: Yeah, sure.

Troy: That's funny. So you've heard that in your urologic training, and then I hear it all the time with toxicology, with overdoses. "The secret to pollution is dilution." So, anyway, it crosses multiple specialties

Dr. Smith: And the orthopedic colleagues will say, when they're rinsing out a joint that's infected, that that's the solution.

Troy: Yeah. There you go.

Scot: So, with kidney stones, what's causing those things? Is it because of something I've eaten or something I'm doing, or are they more hereditary? What's the story on that?

Dr. Smith: Yes.

Mitch: Well, no. That's a really good question. I've got a buddy, he's a listener, and I don't want to go too far into it, but I've seen him go through kidney stones. It seems like he gets them every single year. And I know he does a lot to drink all his water, he's done some things to change his diet, but he still gets them. So what could be causing them other than lifestyle, I guess?

Dr. Smith: So I don't know. Troy, do you want to jump in here? I'm happy to go over my spiel that I give my patients who are the chronic kidney stone guys and even the ones who are first-timers.

Scot: I think we want to hear that, don't we, Troy? I mean, I could listen to Troy anytime. I don't always get to listen to Dr. Smith.

Troy: Scot gets tired of listening to me, so please go on.

Dr. Smith: Man, that was some shade, Scot. Wow.

So when I have folks that come in and we talk about kidney stones, there are a couple of different reasons that people get them. And usually, for folks that are first-timers who've never had a kidney stone before, they meet . . .

The other day I had a patient in his mid-40s who came in, never had a kidney stone, and we started discussing stones. Most commonly for folks who aren't predisposed genetically or have some kind of a metabolic issue, it's usually a hydration issue. And so dehydration will put you at risk for stones.

I usually use the analogy of if you ever made those salt crystals or sugar crystal things as a kid where you had that pot of tons of salt or sugar and you dipped a string in and you made those crystal things. You guys ever do that?

Mitch: Yeah.

Scot: Yeah.

Troy: Yep.

Scot: That's what's going on?

Dr. Smith: It's similar to that, because the more concentrated your urine is, the more stuff that's in there that could form a stone. And all a stone is, is a crystal that forms and it's made of different material. The most common ones are calcium-based. A dilute urine will not form a stone the way that a concentrated urine would. So that's the first thing I tell people to do. To drink plenty of fluids is going to keep them from having a concentrated urine. That's number one.

And I usually say there are four things that you can do to prevent a kidney stone regardless of the kind of stone you make, regardless of why you get them.

Number one is hydration. And I usually tell people you want to make at least two to two and a half liters of urine per day. Now, that's a hard one to do because nobody just measures their urine every day. And so that generally means . . .

Scot: Let alone in liters. I mean, what are we doing with the metric system here? We're in America. Come on.

Dr. Smith: Well, but in medicine we use the metric system, unfortunately. But I usually tell folks if you go get those big packs of water at Costco or the supermarket, those are a half a liter each. Those 16.9-ounce bottles are a half a liter each. So you should be drinking four to six of those a day.

Scot: Yeah, or one of those big sodas. Those are two-liter bottles of soda. Now you're talking.

Dr. Smith: Sure. See, now we're talking things. So if you drink at least 6 of those a day, your body uses between 500 and 750 milliliters of fluid a day for metabolic purposes, and so you're not making urine out of that. That's just what you need to be alive. And so anything above and beyond that gets turned into urine. That's why I say you need to drink two to three liters of water per day. To make two liters of urine, you've got to drink around three liters.

Troy: Now, Scot just mentioned he's going to go start drinking those two-liter bottles to measure it. What about drinking soda? Is that going to increase your risk?

Dr. Smith: So it can, depending on the type of stones you make. Obviously, the more stuff you have in your body that your body has to metabolize and break down and put into the urine, the more stuff is in your urine, the more likely you are to make a stone.

And so, for some folks, they're really predisposed to that, so it can make a difference for them. And for other people, it may not make a huge difference. That's something where when we get to the diet-related stuff I usually mention, but the first thing is just drinking plenty of fluids.

The second thing that anybody can do would be to decrease the amount of salt in your diet. And so that means soda. Oftentimes diet soda in particular has a ton of salt in it, as well as other processed foods. Pre-made stuff that you buy at the supermarket has a ton of salt in it.

Your body gets rid of excess salt in the urine and oftentimes the other solutes, the things that are going to help make stones, will follow that salt out into the kidneys and make urine. So that's another thing that you can avoid.

The third thing you can do is avoid animal protein. Now, that doesn't mean beef. It means any kind of animal protein -- fish, pork, chicken. Those create a high acid load in your system and decrease the pH of your urine. And when your urine pH is decreased, that increases your risk of stones. Stone formation increases when you have a low pH in your urine.

And that leads into the fourth thing that I usually tell people. Alkalinizing your urine in some way with lemon, lime, fresh fruit, berries, things that have citrate in them will cause a base to form in the urine and increase the pH.

So those are the four things you can do. Without knowing what kind of kidney stone you have if you've never had it analyzed and you have chronic stones, those are the four things you can do to decrease your risk of stones.

Scot: So coming back to our core four, kidney stones are caused by the types of foods that we're eating and drinking. It's totally diet based, right?

Dr. Smith: So not necessarily. Obviously, the dehydration thing is huge, but someone who has . . . So Mitch's buddy probably has a metabolic issue where his urine makeup predisposes him to having stones.

And so oftentimes, for folks in that situation, we'll do a 24-hour urine test and look at what's in the urine and what's spilling into the urine to see what's high level. If there are high levels of calcium or high levels of certain chemicals, high levels of nitrogen from animal protein, high levels of just salt, and different things that can predispose you to having stones, we definitely look at those.

Scot: How much does genetics play into whether somebody develops kidney stones or not? I would imagine that there are plenty of people that aren't drinking water and eating high salty foods and never get stones, or is that not true?

Dr. Smith: No, I think there is definitely a genetic component. How strong it is, is very difficult to kind of put your finger on. The literature shows that there can be some predisposition for folks who have family history.

And I've seen that anecdotally in my practice. Folks who come in at a younger age with stones oftentimes have family members who have chronic kidney stones. So I definitely think there's a correlation for those folks. Absolutely.

Scot: And you talked about the different kinds of stones. What's that about?

Dr. Smith: Well, there are a few different kinds of stone. The most common are calcium-based. There are calcium stones, multiple different kinds of calcium stones, but the important part is they're made with calcium.

Now, that doesn't mean don't drink milk, don't eat calcium. You actually want to have a normal amount of calcium, but not overdo it and not underdo it, which has been a misnomer for people. They're like, "Oh, I'll just stop drinking milk, I'll stop eating calcium, and it'll fix my stone problems." And it actually has been shown to make it worse in some of the literature. So you don't want to cut that out completely, but you also want to make sure that you're not eating other foods that may be problematic.

So calcium oxalate is the most common types of stones. And when you have a high oxalate diet . . . So coffee has oxalate, tea, spinach. Dark green, leafy vegetables have oxalate in them. There are other foods that have oxalate. Some people will say, "Oh, you've got to go on an oxalate-free diet," when in reality if you have calcium and oxalate in your gut, your gut can bind those things and it actually gets put out in the stool instead of going into the system. That's why you don't want to cut out calcium completely.

I mean, there are a lot of dynamics to kidney stones that kind of make it difficult, and knowing what type of stone you have can be helpful. So the calcium stones, we can kind of base things on diet.

The other type of stone that we see in folks is uric acid. Those are probably the second most common that I see. Those ones can actually be "melted" with medication and alkalinizing the urine, making the pH of the urine go up. So that's one where if we know that someone makes those and we keep their urine pH up, we can decrease the size and the amount of the stones that they make with the pH of the urine.

Scot: Which stones are the prettiest stones?

Troy: Calcium, of course.

Dr. Smith: They're all beautiful. They're all terrible.

Troy: Well, the calciums are kind of nice and shiny and it almost looks like a pearl.

Scot: Are you serious, Troy? Do they really?

Troy: I don't know.

Scot: I thought maybe you knew.

Troy: I just know they show up really well on an X-ray.

Dr. Smith: They do. That's the calcium.

Troy: Yeah. I don't know how they look when they come out exactly. But I can say hearing this, though, it sounds like the key is, like you said, John, drink lots of water, try to avoid eating too much meat, avoid salt, fruits and vegetables. Those are the keys. I mean, that just kind of gets back to a lot of what we talk about. Just healthy diet in general.

But hearing this, we talked just a little bit about the pain with kidney stones, but I can tell you when I see someone in the ER with a kidney stone, I don't know that I ever see anyone on a regular basis in the ER who has more pain than a person who's there with a kidney stone. You can tell. You walk in the room, they're writhing. They're pacing around the room, kind of holding their side. It's just incredible pain.

Every time I see them, I kind of have the same feeling you do. It's just like, "Hey, I want to do everything I can to avoid this." And if it means drinking tons of water and just watching my diet, it's well worth it just because that looks absolutely miserable.

Mitch: So what are some of the symptoms, I guess? I mean, we're talking about the pain itself and how to prevent them, but what are the actual symptoms? Is it just, "I've got pain in my stomach"? Or where do we feel it and things?

Dr. Smith: Well, I think Troy could probably answer that because he has them come in, but usually it's a pain in the flank, which is kind of the upper outer portion of your back on either side. And as the stone kind of travels down the ureter, that pain can migrate to the low back, even into the groin.

And I usually tell folks when stones are sitting in the kidney, they don't usually cause pain because they're not obstructing. They're not bothering you. But when they start blocking the flow of urine and they get into the ureter, the small tube, your body tries to get rid of that by peristalsing, just the way it does when it moves food through your intestines.

And so at that time, the stone, once it gets into the tube is where you start to have the pain and it usually starts in the flank and then moves down.

Troy: Yeah, and that's exactly what I see. People are kind of holding their sides. So if you were to kind of reach around, hold your sides of your abdomen, that's typically where they're feeling the pain. I push on their stomach, their belly doesn't hurt, they're not really tender, but it's just a deep, severe pain. And they'll tell me it comes and goes, it's sharp, sometimes it's better, sometimes it's worse. John, it's exactly like you mentioned, that spasm where that ureter is spasming. That's when they really seem to have severe pain.

Scot: And then is the treatment painful too? I mean, is this the double whammy of not only does the thing hurt, but the treatment is going to hurt bad as well?

Dr. Smith: Well, what Troy does for people doesn't hurt. They really love Troy. They don't like it when they come and see me after they've seen Troy.

Scot: Okay. Because Troy gives them . . .

Troy: I just give them pain meds.

Scot: And then you send them to John.

Troy: Exactly. But it's great, though, because there is a non-narcotic and non-steroidal anti-inflammatory medication that we give intravenously. And it just works beautifully for kidney stones. So it's not like we're just knocking people out with narcotics. Some people need narcotics, but so many people, I give that medication and they're just like, "Wow. I feel better."

Scot: What's the treatment then, Dr. Smith?

Dr. Smith: So there are a couple of different treatments depending on where the stone is at and different things. I mean, there's a little bit more to it here, some nuance. But if it's moving down and it's relatively small, oftentimes we'll offer people to pass it on their own. We call it medical expulsive therapy. It's not pretty, but it gets rid of the stone.

And so we give them some medication to help the stone pass. And after we do that, we let them kind of do their thing and pass the stone on their own for a couple of weeks. And if it doesn't pass, well, then we bring them back and we offer them surgery. Stones can be . . .

Scot: Ugh.

Dr. Smith: Go ahead.

Scot: No. I just went, "Ugh."

Mitch: Yeah, ugh.

Troy: Two weeks of that. Yeah.

Scot: Yeah. I don't have to say anything other than ugh.

Dr. Smith: I mean, I'll give them a little bit more than two weeks if they're really confident that they're passing it and they're not wanting to do anything surgically.

But the other options that we have are if the stone is visible on an X-ray, just like Troy alluded to earlier, sometimes we can do what's called an extracorporeal shock wave lithotripsy. Some people just refer to it as lithotripsy, where we use an external shock wave beam to break up the stone, and then you still have to pass the fragments. And that's only if we can see it on an X-ray to target and hit it.

Scot: So those are my two options? Either give birth to that stone myself or . . .

Dr. Smith: No, there are other options. I'm just saying those are the two . . .

Scot: Oh, okay.

Dr. Smith: I'm going from least invasive to most invasive here.

Scot: All right. Get them busted into shards or have surgery. Yeah, that's more reasons why to drink more water, I guess.

Dr. Smith: Exactly. So the third option that I offer folks is called a ureteroscopy laser lithotripsy, where we go up with a small, thin, flexible camera and we find the stone and we blast it with a laser.

Scot: Oh, that sounds badass.

Dr. Smith: It's pretty cool.

Mitch: It's all pretty cool, but miserable.

Dr. Smith: Yeah. And usually, with that, they have to put what's called a stent, which is a small, thin, flexible plastic tube from the kidney to the bladder. And they are miserable. I always tell patients, "It's miserable. You keep it in for about a week to let things heal and then you take it out in the office."

Troy: And I think Scot, when he thought that was really cool, I think it's probably worth telling him how you get the laser up to the stone.

Scot: Oh, no.

Mitch: Oh!

Scot: No, I'm good.

Troy: You're good? Okay.

Dr. Smith: Well, there's no cutting, Scot, so you can use your imagination.

Scot: Yeah. Just thread that thing right up there, huh?

Dr. Smith: Yep. Just like throwing darts.

And then the last thing that we do for stones if they've gotten too large to pass and they're in the actual kidney, we can do what's called a percutaneous nephrolithotomy. They use the term PCNL because it's way easier to say. And that's where we make a small incision in the back and we go into the kidney and we actually are able to remove the stone in larger pieces that way.

That's obviously the most invasive way to do it, and we do that for much larger stones. You've got to have a stone that's a centimeter and a half or larger, or at least that much volume of stone in the kidney before we would contemplate doing that.

Scot: Troy, can these stones get so bad that you're going to see somebody in the emergency room that has to have an emergency surgery because they just can't urinate anymore?

Troy: I can't say I see them where they can't urinate, because usually it's just in one of the ureters and so the other kidney is working, although you could have it, I guess. I've rarely seen it where it's so bad that you can really see it's impacted their overall kidney function.

The more concerning thing I see is when you get an infection along with the stone, and those are the cases where they're definitely admitted to the hospital.

But yeah, if it's a really large stone, like John mentioned . . . Usually the cutoff we use is six millimeters, but even there, I think sometimes our urologists will say, "Give it a little time. Let's see what happens." But if they've got a big, centimeter and a half stone just lodged in there, yeah, those are cases where the urologists will admit them and do something sooner rather than later.

Dr. Smith: Good point, Troy. When you have an infection above the stone blockage, those folks can get real sick real quick. And those are the people that emergently get surgery. And oftentimes we don't treat the stone immediately. We treat the infection. We put a stent in and give them antibiotics and come back another day to take the stone out. They're just so fragile as far as their health goes at that point that oftentimes they need antibiotics to clear out that infection before we're able to treat the stone.

But Troy is right. Anything 5 millimeters and under have a 75% to 80% chance of passing on their own. Now, that to be said, I have folks who come in with two-millimeter stones who are unable to pass them and folks with seven-millimeter stones that pass them and they said it wasn't a big deal. So, again, it's all relative to the patient. But once you get these larger stones, definitely surgery is much more frequent for those folks with larger stones.

Scot: Hey, Mitch, we're wrapping this up. Do you have anything you'd like to share?

Mitch: I'm just very uncomfortable and trying to drink my water off camera. That's what I'm doing right here right now.

Scot: You went and got some more water.

Mitch: I did. And I'm saving everyone from the sipping noises, but yeah, a refill was necessary.

Scot: These lifestyle changes that we make, Dr. Smith, is there a percentage of reduction of risk that they will do that we know about?

Dr. Smith: That's a tough one. I don't know that there's an actual percentage of risk. I would say when you do it, if you are a chronic kidney stone patient, we usually follow your 24-hour urines to check your risk assessment. But folks who have a stone and pass a stone and then hydrate themselves can really reduce their risks just by doing those things.

The numbers that I know and usually quote people is if you have a kidney stone that requires surgery, 50% of folks who have that issue will have another episode of a kidney stone within a year. And so that's why I usually tell folks the more you can do to drink and keep them away, the better off you are.

Scot: Well, it was a fun topic. I still don't know which stones are the prettiest stones, which makes me a little bit sad, but that's okay.

Dr. Smith, thank you so much for being on the show, and educating us on kidney stones, and telling us what to do. Would you like to summarize, Mitch? What are you going to do? You're going to drink water. What else?

Mitch: I'm going to just drink all the water and I'm going to make sure that I'm not having too much salt in my diet.

Scot: Watch the processed foods.

Mitch: And watch the processed foods. I need to eat less taquitos.

Scot: And maybe a little lime in your water, it sounds like. Is that right, Dr. Smith?

Dr. Smith: Yeah.

Scot: Get that pH down. Is that what that . . .

Dr. Smith: It won't hurt you.

Scot: No, that's getting that pH up, isn't it?

Dr. Smith: Yeah, pH up. Correct.

Scot: Yeah.

Mitch: Okay. So preventing scurvy and rocks in places I don't want rocks. Got you.

Scot: Dr. Smith, thanks for being on the podcast. Thanks for caring about men's health.

Dr. Smith: Troy, Scot, Mitch, it's always a pleasure. Thanks for having me.

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