Kidney Stones: Your Questions Answered
Online Health Chat with Dr. Manoj Monga
May 11, 2011
Cleveland_Clinic_Host: According to the National Kidney and Urologic Diseases Information Clearing House, nearly three million people visit health care providers and more than half a million people visit emergency rooms for kidney stone problems.
Many of these patients also suffer from recurrent or complex kidney stones that are often debilitating. In these cases, surgical procedures may be an option.
The majority of such kidney stones, depending on their size and location, can be removed with minimally invasive techniques, such as shockwave lithotripsy (SWL), ureteroscopy, or percutaneous surgery. SWL is a relatively non-invasive procedure that uses targeted shock waves to break stones into tiny pieces that are passed naturally in the urine.
Cleveland Clinic urologists were among the first in Ohio to use lithotripsy, and more than 3,000 patients have had lithotripsy at Cleveland Clinic. Additionally, the American Urologic Association has designated Cleveland Clinic as a national lithotripsy training center for physicians.
Dr. Manoj Monga joined the Glickman Urological & Kidney Institute in September 2010, and specializes in kidney stone disease, minimally invasive treatments for nephrolithiasis, endoscopic procedures for ureteropelvic junction obstruction, endoscopic procedures for upper tract transitional cell cancer, and the prevention of nephrolithiasis.
Cleveland_Clinic_Host: Welcome to our Online Health Chat with Dr. Manoj Monga. We are thrilled to have him here today for this chat. Let’s begin with some of your questions.
mvola: Are kidney stones hereditary?
Dr__Manoj_Monga: Yes. If you have a family member with stones you are at a higher risk for stones.
jennifer: What are the symptoms of kidney stones? How would I know (or suspect) that I had them?
Dr__Manoj_Monga: Kidney stones cause pain when they start to move. If they are not moving, you may not know you have them. On occasion, you or your doctor might notice some blood in the urine.
If the stones start to move, they cause a "colicky" pain that usually starts in the flank (back, below the ribs) and may radiate down to the lower abdomen. Sometimes during this, they also cause nausea and vomiting.
sweetpea: What causes children to develop kidney stones?
Dr__Manoj_Monga: The most common findings in children who form stones are not drinking enough fluids and having high calcium in the urine. This does NOT mean that they should limit their calcium intake. Medications may be helpful.
painters2: I have read that half the people who get a kidney stone will have another within about five years? Why is this? Why are certain people prone to getting kidney stones?
Dr__Manoj_Monga: The risk for stones is a combination of genetics and environment (mainly what you eat and drink). Because of this, you are at a risk of recurrent stones. Ten percent per year will have a recurrence. One can DECREASE this risk by following a special diet and, on occasion, using medications.
DCane7: Are kidney stones preventable? How?
Dr__Manoj_Monga: The risk of kidney stones can be decreased significantly, but not eliminated. A combination of diet and at times medications is utilized. The main "general guidelines" are:
- Drink plenty of fluids.
- Limit your salt.
- Eat lemons/limes/oranges.
- Maintain appropriate calcium intake.
blank_slate: A kidney stone was found by IVP. My doctor was going to manipulate it a few weeks later; but at that time, he could not find it. How can a kidney stone just disappear? I did not pass it naturally.
Dr__Manoj_Monga: Stones may crumble and pass. One would notice it pass only with a strainer. If you were straining your urine and didn't see it pass, then it might be worthwhile to get a new X-ray to confirm it is gone. A CT scan will be more accurate than an IVP.
joeT3: Is an IVP able to differentiate between a ureter stone and a ureter lesion (blockage)?
Dr__Manoj_Monga: The best way to differentiate a stone from tumor/stricture in the ureter is a CT urogram. CT is 99 percent accurate to diagnose stones. IVP is not as accurate for stones, but is very good for tumors and strictures. The accuracy of IVP for stones is about 70 percent to 80 percent.
kevin90: I had an ultrasound done recently that indicated a kidney stone. The doctor then did an IVP, which did not show a stone. Which test is more accurate?
Dr__Manoj_Monga: Neither. Both are about 70 percent to 80 percent accurate. You should get a CT scan if you are having pain. On the other hand, ultrasound is a useful test to follow stones, if one wants to limit the amount of radiation.
BeachTime11: Does having lithotripsy just result in having more, smaller, and just as painful stones versus one large one?
Dr__Manoj_Monga: The goal of lithotripsy is to break the stone(s) into fragments that are the size of grains of sand, which should pass with minimal pain. This is the case in 70 percent to 80 percent of patients. The remaining patients may have larger fragments that do cause pain as they pass, or may have difficulty passing the fragments.
JRD526: Who is a good candidate for shockwave lithotripsy?
Dr__Manoj_Monga: There are many variables that are related to both the patient and the stone:
Patient: not obese
- not on anticoagulants (blood thinners)
- not pregnant
- normal anatomy for the kidney and ureter
Stone: best stone for shockwave is between 5 to 15mm
- less than 5mm - may be difficult to target
- 15 mm - more likely to fail (We can also measure the hardness and depth of the stone on your CT scan. These can help predict whether shockwave will work.)
- Location of the stone - lower pole - harder for fragments to pass
collie3: I had a large kidney stone removed with laser and cystoscopy. A stent was put in and is to stay for about four weeks. How long should I expect to see blood in my urine?
Dr__Manoj_Monga: It is not uncommon to see some blood in the urine until after the stent is removed. If you see bright red blood or clots, that would be cause for concern.
Billy_Bob: What is the purpose of a stent after surgery? It is very uncomfortable. Is it necessary or can I request to have it removed?
Dr__Manoj_Monga: A stent is placed to allow urine to drain while any swelling in your ureter subsides. For an uncomplicated surgery, it is typically left in for 5 to 14 days. You can request to have it removed, but your urologist will counsel you on the risks, based on what he or she saw when placing the stent. Unfortunately, you are right, 80 percent of patients with stents will have some discomfort. For distal ureteral stones, we can sometimes do the surgery without leaving a stent if the ureter "looks good" at the end of the surgery.
pasta: I have a large stone in the ureter that is not passing. The doctor said that if it does not pass soon, we would discuss other treatment options. What is the best option for a large stone in the ureter? Lithotripsy and cystoscopy were mentioned.
Dr__Manoj_Monga: We would look at your CT scan. If the stone is <10mm in size, in the proximal ureter, or the hardness on CT (hounsfield units) < than 1000, and the depth of the stone <12 cm, then shockwave is a great option. If the answer to any of the above is "no," you might consider and endoscopic procedure (ureteroscopy) instead.
happy_days: My son was told he has high levels of calcium in his urine What does this mean and how can it be treated? Is this related to his diet or some other problem?
Dr__Manoj_Monga: The first step is to check a PTH level to make certain this hormone is normal. If it is, then there are diet changes one can try (mainly LIMIT SODIUM), along with a fish oil supplement. If this is unsuccessful, then usually we use a "thiazide" type medication to lower the urinary calcium.
happytrails: I recently read something about thiazide diuretics being used for medullary sponge kidneys, and that they are effective in preventing stone formation. What are your thoughts?
Dr__Manoj_Monga: They are very effective, especially if you are on a 24-hour urine collection, and your urine calcium was high. In this situation, thiazides can be very helpful.
spalding: Is there anything that can be done to help speed up the stone into passing?
Dr__Manoj_Monga: Alpha-blockers are a type of medication that can speed up stone passage, decrease pain, and decrease the risk of surgery. The two that have been studied the most are Flomax® (tamsulosin) and Uroxatral® (alfuzosin Hydrochloride).
jumpon: What affect do calcium channel blockers have on kidney stone formation, if any?
Dr__Manoj_Monga: I am not aware of any effect on stone formation. Calcium channel blockers have been used to help with stone passage, though they are not as effective as alpha blockers.
SunshineGrl5: I read that eating lemons and adding lemon juice to drinks and foods can help "eat away" at the calcium used to make kidney stones. Is this a viable option to prevent recurring stones?
Carolyn_Snyder_MPH_RD: Adding citrates -- in the form of citrus juices, such as lemon, lime, or orange -- does change the urine concentration and does aid in preventing kidney stones. One half cup of concentrated lemon juice in about 1 liter of water per day, over the course of the day, is beneficial.
JackN02: I’ve heard that drinking olive oil with water and lemon can help you pass larger stones. Is this true?
Carolyn_Snyder_MPH_RD: 100 ounces of water with 1/2 cup of concentrated lemon juice is recommended, but the olive oil is not proven to be beneficial.
FlipFlop9: Are there certain foods that I should avoid to decrease my chances of getting kidney stones again? Are there any foods I should be sure to include in my diet?
Carolyn_Snyder_MPH_RD: Based on the stone composition, the dietary restrictions are personalized to the patient. The majority of stones are calcium oxalate stones, so a diet higher in calcium and lower in oxalate is suggested. Higher oxalate foods include spinach, strawberries, tea, dried peas and beans, nuts and nut butters, and wheat bran. For a specific diet for stone prevention, you should schedule an appointment with a registered dietitian to tailor a diet to your specific needs. Just drink to dilute!
yen45: I have been using dietary modification to help prevent kidney stones. For me, it helps. Is there somewhere where I can get comprehensive information as to the oxalate levels in common foods? I find this information very hard to come by.
hardly: I drink a lot of iced tea. I have read that Indian tea is high in oxalates, but is this also true in regular teas?
Carolyn_Snyder_MPH_RD: Yes. Tea is high in oxalate, with the exception of some herbal teas, so it is recommended that if you have a history of calcium oxalate stones to limit tea. Beware of some herbal teas, as they are linked to stones and should be limited as well. Try the lemon or orange zest!
Kidney Stones and Other Conditions
plasterer: I have medullary sponge kidneys with a lot of stones. Is there a way to get rid of all of these stones without waiting until they decide on their own to pass? Is having a large number of stones present at one time dangerous to my kidneys and 'renal health'?
Dr__Manoj_Monga: Stones are dangerous if they are causing blockage of the kidney and they go untreated. Usually, stones in the kidney are NOT causing blockage and could be observed if not causing pain. With medullary sponge kidney, we can sometimes look in with a scope and use a laser to unroof the stones.
DRK787: What is the relationship between IBD and kidney stones?
Dr__Manoj_Monga: There is a higher risk of stones with IBD. One reason is that there is low urine volume, as much of the fluids are lost in the GI tract. Secondly, urinary citrate, an inhibitor of stones, is often low. Lastly, urinary oxalate may be high.
part_fish: I have had two kidney stones in the past year and my doctor said to watch my calcium intake. I just found out that I am pregnant. Wouldn't limiting my calcium intake be bad for the baby? I have an OB appointment in a couple of weeks, but was wondering if there was anything to help prevent stones beyond limiting calcium intake?
Carolyn_Snyder_MPH_RD: Actually, calcium three times per day is now recommended if the patient is prone to calcium oxalate stones. The calcium in the dairy products binds with the oxalate-containing foods, thereby excreting the oxalate through the GI tract rather than the urinary tract system. Make sure you have adequate fluid intake of at least 64 ounces per day or until urine is dilute and odor-free. Remember, with the additional metabolic load -- the fetus -- your fluid intake may need to be further increased. Be aware of your sodium intake, and limit it to 1500 mgs per day total. Congratulations on the baby!
p24: Does Cushing's syndrome have any effect on the kidney's/kidney stones? I have had three stones pass in the past year and was recently diagnosed with Cushing's. Just wondering if there was any correlation?
Dr__Manoj_Monga: Kidney stones can be the first manifestation of Cushing's. Calcium leaks out of the bones (osteoporosis) and into the urine.
katie987: What conditions can cause hydroxyapatite stones? Can it be purely dietary?
Dr__Manoj_Monga: Hydroxyapatite stones are a form of "calcium phosphate stones." Commonly, the urine pH is high and the urinary calcium is low. Each of these things can be modified by diet; however, you should also have PTH hormone level checked. Medications may also be helpful.
999inja: Is there any correlation between an increased alkaline phosphatase and kidney stones?
Dr__Manoj_Monga: Stones can be linked to osteoporosis. Apart from that link, I do not know of any relationship with alkaline phosphatase.
jojo: Can chronic pain in the testis derive from kidney stones?
Dr__Manoj_Monga: A stone in the ureter can cause referred pain to the testicle. However, this should not be the cause of chronic testicular pain. If a CT scan did not show a stone in your ureter, then the pain in the testicle is not being caused by a stone.
hold_on: I am a 35-year-old male and have had several kidney stones. I currently have three that are still in the kidneys. I am in chronic pain, but the doctors say there should be no pain as the stones are still in the kidneys. What else could cause this pain?
Dr__Manoj_Monga: Other things that commonly cause pain in the same region as the kidney are musculoskeletal issues or gastrointestinal issues. Unfortunately, it is often difficult to define the exact cause of the pain. If you have larger stones (>4mm), it is sometimes worthwhile to remove them, even if they are not visibly blocking the kidney. Sometimes people do get relief.
haley: I was in severe pain when I went to see the doctor. I did not have stones but they found calcium deposits (like sand) in my left kidney. Could these calcium deposits or passage of them cause severe pain?
Dr__Manoj_Monga: Yes. Even a very small deposit passing could have caused pain. The sign that you have residual deposits in your kidney indicate a strong possibility that if your pain was in the characteristic location for kidney pain, this was the cause.
black_on_white: I know that many people pass kidney stones naturally. Is it better to go to a doctor with a suspected kidney stone or is it OK to just wait until it passes naturally?
Dr__Manoj_Monga: Reasons to see a doctor:
- To make certain that it is a stone and not something else
- To get screened for kidney function – To make certain your kidneys are working well
- To start a medication to help you pass your stone, if necessary
- To work together to prevent new stones
- To have a resource for surgery if it turns out that you do need surgery.
Lucky225: How much water should I drink to prevent the onset of kidney stones?
Carolyn_Snyder_MPH_RD: Try 100 ounces of water over the course of the day, as well as at least 8 ounces of water midway through the night. The goal is to keep the urine the color of a very light lemonade and odor-free - an indicator that the urine is not concentrate.
TravelGuy6110: Once a stone reaches the bladder, how long should it take to come out? I now have a constant urge to use the restroom.
Dr__Manoj_Monga: Once it reaches the bladder it should come out within one to two days. The exception would be a man with a large prostate who has difficulty urinating. In this situation, it might take longer, or may not pass.
owardS: What dangers do regularly having kidney stones present to the body, if any?
Dr__Manoj_Monga: As long as they pass, the main issue is the pain and inconvenience. It is rare for stones to lead to renal failure.
please: Is it possible to have a kidney stone for years without it passing?
Dr__Manoj_Monga: Yes. Stones may sit in the kidney for many years and not pass, and may not cause pain.
gone_fishing: In general, how long is the 'life' of a kidney stone? How long does it take to form and eventually pass through the body?
Dr__Manoj_Monga: The "life" of a kidney stone is highly variable. I have seen large stones (3-4 cm) form within three months. On the other hand, many stones form over the course of years, and may never pass. The rapidity of stone formation is related to your "metabolic risk," which can be gauged by a 24-hour urine test. We do not know why/when stones decide to pass.
Cleveland_Clinic_Host: I'm sorry to say that our time with Dr. Manoj Monga is now over. Thank you again Dr. Monga for taking the time to answer our questions today about kidney stones.
Dr__Manoj_Monga: Thank you for joining us today. I appreciate your insightful questions and wish you the best in preventing and managing your stones.
Carolyn_Snyder_MPH_RD: We hope this has been beneficial, and we appreciate your variety of questions. Remember, drink water all day long, keep urine dilute, and limit your sodium. Thank you for your participation.
If you would like to make an appointment with Dr. Monga or any of the urologists in the Glickman Urological & Kidney Institute at Cleveland Clinic, please call 800.223.2273, ext. 45600, or request an appointment online by visiting www.clevelandclinic.org/appointments. Thank you!
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