Kidney Stones: Symptoms, Risk Factors and Treatment Options for Patients

This is Weekly Dose of Wellness, brought to you by MemorialCare Health System. Here's Deborah Howell.

Melanie Cole (Host): This is Melanie Cole sitting in for Deborah Howell today, and according to the National Kidney Foundation, more than half a million people visit emergency rooms each year for kidney stones. My guest today is Dr. Gaytri Gandotra. She's a nephrologist with MemorialCare Orange Coast Medical Center. Dr. Gandotra, what is a kidney stone and how do they form?

Gaytri Gandotra, MD: Hi, how are you? Good morning. Before I start, I want to just reiterate what you mentioned about the fact that kidney stones are very common and it's very common, especially in the U.S., and becoming more and more common in developed countries is occurring in about 8% to 15% of people. Kidney stones vary in people aged 20 to 60 years. It's more common in men. So kidney stones form… Let me explain to you a little bit about the structure of a kidney. The kidney has a million functional units called nephron, and each nephron has two parts. It has a glomerulus and a tubule. The tubule filters many solutes, so our kidney filters many solutes such as sodium, potassium, uric acid, and phosphorus. So when we have too much of a particular solute filtering through the kidney, it starts to form little crystals inside the tubules, kind of like the piping under your sink. So as those crystals grow in size, it eventually forms a kidney stone. Now, our body also produces a natural stone inhibitor called citrate. So you can either have too much of a particular solute filtering through your kidney, such as sodium or calcium, or some patients don't have enough citrate that they form. And therefore, they don't have enough stone inhibitor and they form kidney stones.

Melanie Cole (Host): So what are the risk factors? You mentioned that they're more common in men. Is there anything that would predispose men and or women to kidney stones? And does your diet make a big difference in the formation of those stones?

Gaytri Gandotra, MD: There are eight different types of kidney stones, more than eight different types of kidney stones, and 80% of them are calcium-containing stones. Diet, of course, is very important. The number one factor which contributes to stone formation is dehydration. People just don't drink enough water. Good old H2O. A lot of people say, I drink, I have soup and coffee and tea, but basically they need to have enough water. So dehydration is the number one factor which contributes to stones. Other factors are high salt intake. So patients typically, there are many patients who eat a high amount of processed foods. Now I said that 80% of stones are calcium-containing stones. So why are we worried about salt? That's because sodium and calcium float together. So the more sodium you eat, i.e. salt, the more calcium gets filtered through your kidney. Therefore, you form a kidney stone. So what we tell patients is to cut out the salt or cut out the processed food. Other things that contribute to stone formation, there's a type of stone called calcium oxalate stones. Oxalate is present in spinach, tea, dark chocolate. I mean, you won't get a stone if you eat these in moderate amounts, but in high intake, you can develop a kidney stone. People that have a heavy meat diet, animal proteins such as beef and pork can have high uric acid level. Uric acid leads to gout and high uric acid also can lead to the formation of kidney stones. So those are just a few common examples, but of course there's so many more which if one is known to have a stone, they can discuss all these with their nephrologist.

Melanie Cole (Host): So what would be some of the signs and symptoms? You know, we've seen on TV, Dr. Gandotra, that people are in pain or men are hoping that the stone passes on its own. So speak about what symptoms we might recognize or signs that would say, okay, this is possibly what's happening.

Gaytri Gandotra, MD: Right. So the most classic symptom is pain, severe pain. Patients will say that it's the worst pain they've ever experienced. It's typically our kidneys are about the size of our fist and they're located in our back on either side of our spine, just below the ribcage. So the pain might start there and it might radiate anywhere down the abdomen into the groin, depending upon the location of the stone. Patients will sometimes complain of blood in their urine, that they have had blood, which they had in their urine... perhaps one or two days ago, and then it resolved. But the most common symptom is discomfort. Patients can also have abdominal pain, which takes them to the emergency room, nausea, vomiting, or other complaints as well.

Melanie Cole (Host): And then what would you do to diagnose them? And then what are the treatment options? Because as we said before, sometimes it's a watch and wait thing, or sometimes there are treatments. Speak about when you might administer treatments and how do you find out that someone has a stone?

Gaytri Gandotra, MD: Right. So if you suspect that someone has a stone, typically do an imaging study, perhaps an x-ray. Some stones may not show up in x-ray or the gold standard is the CT scan. A CT scan will show us the location of the stone, the size of the stone, and based on that, we can proceed with treatment. I can't say this for all patients, but in general, smaller stones will pass on their own, stones that are less than 5 millimeters in size. So we ask patients to drink lots of water, cut out the salt, and there isn't much intervention we can do for those stones that are less than 5. For stones that are between 5 to 10 millimeters in size, we try a wait and watch and dietary modification, pain control, symptomatic control. If it still doesn't get better, then we refer them to a urologist. A stone that's greater than 10 millimeters, we typically go straight to the urologist and then they can proceed with discussing treatment options. Sometimes they do a lithotripsy or you might have heard people say that they zap the stone, break them up into smaller pieces so that they eventually pass. But that's the way to treat a stone. But the way to prevent a stone is basically by dietary modification.

Melanie Cole (Host): Can recurrent kidney stones lead to kidney disease or chronic kidney problems, doctor?

Gaytri Gandotra, MD: Yes, if you have had enough stones that are present in many different nephrons throughout your kidney, eventually you can develop what we call chronic kidney disease. The number that we look at in the blood for the kidney is called the creatinine, the lower, the better. But if you have enough stones in your kidney, which don't pass and that are very small, your creatinine can begin to increase over time and you can develop kidney disease. Yes.

Melanie Cole (Host): So wrap it up for us then, Dr. Gandotra, with your best advice about preventing kidney stones in the first place and what you want the listeners to take away from this episode.

Gaytri Gandotra, MD: Right. So it would be two things: first is to make sure you stay hydrated and drink at least two liters of water. If you have had a stone or if you're at risk for stones, you need to have at least two liters of water a day and a low salt diet. A low salt diet is 2,400 milligrams of sodium a day. So, for example, if someone eats a loaf of bread, they look at the food label, it says there's 100 mg of sodium for one slice. That's 100 of your 2,400 a day. Now, you can either count that, but for busy people, they may not have time for that. So I tell patients, just, you know, eat out less, you know, cook food from scratch. There's natural salt in fruits and vegetables and don't eat processed food. And so a low salt diet and two liters of water will really take you a long way and prevent you from developing a kidney stone.

Melanie Cole (Host): Thank you so much, doctor, for joining us today, for sharing your expertise and explaining so very well about kidney stones and mainly the prevention of kidney stones in the first place. Thank you again. You're listening to Weekly Dose of Wellness. For more information or to listen to more podcasts in the series, please visit memorialcare.org. That's memorialcare.org. I'm Melanie Cole. Thanks so much for tuning in.