Posts Tagged ‘kidney stones’

Medical “Urban” Myths in Urology

December 1, 2018

Andrew Siegel MD  12/1/2018

I am pleased to announce that with this entry I have surpassed 400 blogs composed over the past seven years.

Myth:  a widely held but false belief or idea; a misrepresentation of the truth; a fictitious or imaginary thing; exaggerated or idealized conception

thank you Pixabay for image above

Part I of today’s entry confronts widely held but false medical concepts that run rampant in the general population. Part II addresses widely held but false medical concepts that run rampant within the medical field. The medical mythology I attempt to debunk is largely urological in nature.

General population medical myths: Some myths are perpetuated by the general (non-medical) community, consisting of erroneous beliefs and inaccurate presumptions. These falsehoods often require a great deal of physician time in an effort to disabuse patients of them. 

Medical community medical myths: Some aspects of the practice of medicine are on the basis of customs perpetuated by medical personnel (most often not physicians) that seem logical or justified and ultimately become accepted dogma. However, they often do not hold muster, crumble under scientific scrutiny and can be categorized as medical myths.   


“A vaccine caused my child’s autism.”

(This is a non-urological myth, but nonetheless needs to be addressed.)

Myth: Vaccines, particularly MMR (measles, mumps, rubella) cause neurological injuries including autism spectrum disorder.

Reality: Scientific evidence overwhelmingly shows no correlation between vaccines in general, MMR vaccine in specific, and thimerosal (a mercury-based preservative) in vaccines with autism spectrum disorders or other neuro-developmental issues. 

We have come a long way on the immunization and vaccination front, wiping out a significant number of diseases completely.  In children, vaccines have been among our most effective interventions to protect individual as well as public health. What a great means of reducing  risk for certain infections that are potentially lethal, if not capable of incurring significant morbidity.  Vaccinations are now available for hepatitis A and B, diphtheria, tetanus, pertusis, polio, hemophilus, measles, mumps, rubella, varicella, meningitis, cervical cancer/human papilloma virus, influenza and pneumococcal pneumonia and herpes zoster (shingles).

“Doing a prostate biopsy will spread any cancer that may be present.”

Myth: Using a needle to obtain tissue samples of the prostate allows cancer cells to seed and implant along the needle track, or alternatively, into blood or lymphatic vessels. 

Reality: Although this is a theoretical consideration, the truth of the matter is that based upon millions of prostate biopsies performed annually in the USA, the incidence of seeding is virtually non-existent and the potential risk can be thought of as being negligible at best.

“Cancer spreads when exposed to oxygen.”

Myth: When a body is opened up and exposed to oxygen any cancer present can readily spread.

Reality: There is no scientific evidence that supports cancer advancing because of exposure to air/oxygen.  At times, upon doing an exploratory surgery, more cancer is discovered than was anticipated based upon imaging studies. This has nothing to do with the surgical incision nor exposure to air/oxygen, but is simply on the basis of cancer that did not show up on the diagnostic evaluation.

“All prostate cancer is slow growing and can be ignored.”

Myth: Prostate cancer grows so slowly that it can be disregarded. 

Reality:  Every case of prostate cancer is unique and has a variable biological behavior.

Yes, some are so unaggressive that no cure is necessary and can be managed with surveillance; however, others are so aggressive that no treatment is curative, and many are in between these two extremes, being moderately aggressive and highly curable. A major advance in the last few decades is the vast improvement in the ability to predict which prostate cancers need to be actively treated and which can be watched, a nuanced and individualized approach.

Those who feel that prostate cancer should not be sought out and treated should be attentive to the fact that it is the second leading cause of cancer death, with an estimated 30,000 deaths in 2018, and furthermore, that death from prostate cancer is typically an unpleasant one


“Drink lots of fluids to flush out kidney stones.”

Myth: Drinking copiously will help promote passage of kidney and ureteral stones. The rationale of this advice is that by hydrating massively, a head of pressure will be created to help passage of a stone present in the kidney or ureter.

Reality: The presence of a stone often causes urinary tract obstruction.  Over-hydration in the presence of obstruction will further distend the already bloated and inflated portion of the urinary collecting system located above the stone. This increased distension can exacerbate pain and nausea that are often symptoms of colic. The collecting system of the kidney and the ureter have natural peristalsis—similar to that of the intestine—and over-hydration has no physiological basis in terms of helping this process along, being pointless and perhaps even dangerous.  Drinking moderately in the face of a kidney or ureteral stone is sound advice.

“Everyone must drink 8-12 glasses of water a day.”

Myth: Many sources of information (mostly non-medical and of dubious reliability) dogmatically assert that humans need 8-12 glasses of water daily to stay well hydrated and thrive.

Reality: Many people take the 8-12 glass/day rule literally and as a result end up in urologists’ offices with urinary urgency, frequency and often urinary leakage. The truth of the matter is that although some urinary issues are brought on or worsened by insufficient fluid intake–including kidney stones and urinary infections–other urinary woes are brought on or worsened by excessive fluid intake, including the aforementioned “overactive bladder” symptoms.  Water requirements are based upon ambient temperature and activity level. If you are sedentary and in a cool environment, your water requirements are significantly less than when exercising vigorously in 90-degree temperatures.

Humans are extraordinarily sophisticated and well-engineered “machines” and your body lets you know when you are hungry, ill, sleepy, thirsty, etc.  Heeding your thirst is one of the best ways of maintaining good hydration status, in other words, drinking when thirsty and not otherwise. Another method of maintaining good hydration status is to pay attention to your urine color.  Urine color can vary from deep amber to as clear as water.  If your urine is dark amber, you need to drink more as a lighter color is ideal and indicative of satisfactory hydration

“When a patient needs to have a catheter placed because he or she is unable to urinate, clamp the catheter intermittently to allow for gradual drainage instead of allowing it to drain at once.”

Myth: Rapid bladder decompression with a catheter can cause problems including bleeding that may require intervention, kidney failure and circulatory collapse. 

Reality: Science has clearly shown that concerns for kidney failure and circulatory collapse due to rapid bladder decompression are untruths.  Yes, on occasion some bleeding can occur (with or without) rapid decompression, but it is usually self-limited and inconsequential.

“A patient is experiencing leakage around a urinary catheter, so it must be too small and replaced with a larger one.”

Myth: A catheter that leaks needs to be replaced with a larger bore catheter so as to provide a better seal and reduce the leakage. This practice is commonly applied in nursing homes where many patients have long-term indwelling catheters for a variety of reasons.

Reality:  Leakage of urine around indwelling catheters is a common scenario. Although it can be due to a blocked catheter, most often the cause is bladder spasms induced by the catheter or catheter balloon irritating the bladder. The sensible management is to irrigate the catheter to ensure no obstruction, deflate the balloon to some extent, and thereafter consider the use of a bladder relaxant medication to minimize the bladder spasms.  The best practice is always to use the smallest catheter that is effective and remove it as soon as feasible. The longer a catheter stays in, the greater the chance for infections and long-term catheters that are upsized are clearly associated with urethral erosion and urethral stricture (scarring).

“If a patient has bacteria in the urine they must have a urinary infection that needs to be treated.”

Myth: There are bacteria present in the urine on urinalysis, so there must be an underlying infection that demands antibiotic treatment.  This is one of the medical myths perpetuated by internists and general practitioners.

Reality: The thought process that the presence of bacteria in the urine without symptoms means an infection is erroneous. It is vital to distinguish a symptomatic urinary infection from asymptomatic bacteriuria. Asymptomatic bacteriuria, common in elderly and diabetics, is the presence of bacteria within the bladder without causing an infection. This does not require treatment, which is futile and promotes selection of resistant bacteria.  Asymptomatic bacteriuria should be treated only in select circumstances:  pregnant women; in patients undergoing urological-gynecological surgical procedures; and in those undergoing prosthetic surgery (total knee replacement, etc.).

An extension of this myth is that bacteria in the urine in the face of an indwelling catheter is an infection that must be treated. The reality is that in the vast amount of cases, this is bacterial colonization without infection.

Bottom Line: Lay and even medical populations are subject to medical myths—mistaken beliefs that are often passed down like memes with little to no basis in fact. These myths have no place in the art and craft of medicine and need to be challenged with real science.  

“What is dogma today is dog crap tomorrow.”

Wishing you the best of health,

2014-04-23 20:16:29

A new blog is posted weekly. To receive a free subscription with delivery to your email inbox visit the following link and click on “email subscription”:

Dr. Andrew Siegel is a physician and urological surgeon who is board-certified in urology as well as in female pelvic medicine and reconstructive surgery.  He is an Assistant Clinical Professor of Surgery at the Rutgers-New Jersey Medical School and is a Castle Connolly Top Doctor New York Metro Area,Inside Jersey Top Doctor and Inside Jersey Top Doctor for Women’s Health. His mission is to “bridge the gap” between the public and the medical community.

Dr. Siegel has authored the following books that are available on Amazon, iBooks, Nook and Kobo:

MALE PELVIC FITNESS: Optimizing Sexual & Urinary Health

THE KEGEL FIX: Recharging Female Pelvic, Sexual and Urinary Health 

PROMISCUOUS EATING: Understanding and Ending Our Self-Destructive Relationship with Food


These books are written for educated and discerning men and women who care about health, well-being, fitness and nutrition and enjoy feeling confident and strong.

Dr. Siegel is co-creator of the male pelvic floor exercise instructional DVD (female version is in the works): PelvicRx

New video on female pelvic floor exercises:  Learn about your pelvic floor


Are You A Kidney Stoner? Update On Technological Advances

January 30, 2016

Andrew Siegel MD 1/30/16

Continuing on the theme of technological advances in medicine, today’s entry is on innovations in the diagnosis and management of kidney stones. Kidney stones cause excruciating pain, on par with the most painful human experiences– childbirth, broken bones, gout and impaired blood flow to organs.  Kidney stones are a common affliction with about 10% of Americans having experienced their misery. The good news is that most will pass spontaneously, without the necessity for surgical intervention. The other welcome news is that if surgery is required, it is minimally invasive—open surgery for kidney stones has virtually gone by the wayside.

What’s new in the world of kidney stones?

  1. Our recognition that lifestyle factors are major risks
  2. New and improved imaging techniques
  3. Technological refinements in surgical management
  4. Medical “expulsive” therapy to help stone passage

It is now well understood that although there are many causes of kidney stones, lifestyle factors are of paramount importance. This includes body weight, dietary habits and the quantity of fluids consumed. The prevalence of stone disease has DOUBLED in the last 15 years, paralleling the epidemic of obesity and type II diabetes. The more obese you are, the more likely it is that you will experience a kidney stone and the more difficult it will be to effectively treat it. Why is this so?  Obesity has metabolic consequences including increased urinary excretion of calcium, oxalate and uric acid (all common stone constituents); additionally, the obese population tends to consume excessive protein and salt, further increasing stone formation risk.  Another key risk factor is not consuming sufficient volumes of fluid to maintain a well hydrated state.

The diagnostic tools used to evaluate kidney stones have advanced considerably. Years ago, the imaging choice was intravenous urography (a series of x-rays taken after injecting contrast in a vein), which has been supplanted by unenhanced abdominal computerized tomography (CT) urography, a more sophisticated means of visualizing the anatomy of the urinary tract that does not use contrast (thus avoiding the potential risks of contrast) and has recently evolved further in terms of reduced radiation exposure. It precisely pinpoints the size and location of the stone and the extent of the obstruction. It provides insight into the mineral composition of the stone and also images the other organs in the abdomen and pelvis aside from the urinary tract.


CT image of patient with stones circled in red in the lower poles of both kidneys, yellow arrow points to right kidney, blue arrow to left kidney.

In terms of stone evaluation, ultrasonography affords the advantage of less expense and no radiation, but is not on a par with CT imaging in terms of diagnostic capability.

sono kidney stone

Ultrasound image of kidney with stone circled in red; blue arrows point to border of kidney.

Minimally invasive techniques to manage kidney stones are now the norm.  Shock wave lithotripsy uses fourth generation machines that generate and focus external shockwaves at the stone.  This procedure is done under sedation, using fluoroscopy (real-time x-ray imaging) to image the stone, resulting in fragmentation of the stone into pieces that can be passed. Ureteroscopy and laser lithotripsy, done under general anesthesia, is a procedure in which a narrow lighted instrument is passed up the ureter (tube connecting the kidney to bladder) to directly visualize the stone and a laser fiber is used to pulverize the stone into pieces.  This procedure has benefited from miniaturized telescopes with increased flexibility, improved optic lens systems and fiber-optic light sources as well as advances in laser technology.

Medical expulsive therapy is now routinely used to help facilitate the passage of the stone or stone fragments. Alpha-blocker medications including Flomax, Uroxatral and Rapaflo, traditionally used to improve urinary symptoms due to prostate enlargement, are utilized “off label” to help relax the smooth muscle of the ureter and aide stone passage.

Groans, moans and other symptoms

Colicky pain results when a stone gets lodged in the ureter during the process of passage. Because of excruciating pain and the inability to find a comfortable position, stones frequently result in a visit to the emergency room. Other typical symptoms are sweating, nausea and vomiting, blood in the urine and urinary urgency and frequency. In the emergency department patients are usually hydrated intravenously, given pain medications and undergo CT imaging. Most kidney stones can be managed on outpatient basis with patients sent home on pain medication, an alpha-blocker medication and a strainer to capture the stone.

Will my stone pass?

Whether a stone will or will not pass is dependent upon factors including stone size, shape, and ureteral anatomy. 70% of stones less than 5 mm and 50% of those between 5–10 mm will pass, given sufficient time. The smoother and less irregular they are, the more easily they will pass. Passage is also influenced by the internal diameter of the ureter and the nuances of ureteral anatomy. Once a stone passes into the urinary bladder, passage out the urethra (tube from the bladder out) is usually rapid and painless.

Why do stones form?

Kidney stones form when minerals normally dissolved in the urine crystallize into solid particles. It starts out as a tiny “grain” that grows because the stone is bathed in mineral-rich urine that laminates mineral deposits around the grain. This crystal formation often occurs during periods of dehydration, typically prompted by summer heat, exercise, saunas, hot yoga, diarrhea, vomiting, being on bowel prep for colonoscopy, etc. Another big culprit is excess Vitamin C, which is converted into oxalate, one of the components of calcium oxalate stones, the most common stone variety.  Vitamin C is not stored in the body and any excess ends up in the urine in the form of oxalate. Other stone promoting factors are excessive dietary protein, fat and sodium intake. Inflammatory bowel disease and previous intestinal surgery increase the risk for stones.  Urinary infections with certain bacteria can promote stone formation. Parathyroid gland issues and high serum calcium levels increase one’s risk. Some stones have a genetic basis.

When to intervene?

If a stone does not pass in a reasonable amount of time and causes continued symptoms, it will require active intervention. Aside from unremitting pain, other reasons for intervention are unrelenting nausea and vomiting with dehydration, larger stones that are not likely to pass, significant obstruction of the kidney, a high fever from a kidney infection that does not respond to antibiotics, a solitary kidney and certain occupations that cannot risk impaired functions such as airline pilots.

What about recurrent stones?

Although the majority of people with a kidney stone will have only one isolated episode, about 35% will experience recurrent episodes. Because of the possibility of recurrence, it is important to identify the underlying metabolic causes in order to implement prevention strategies. For this reason it is important to analyze the mineral content of the stone and certainly for recurrent stones, to collect urine for 24 hours to do a metabolic evaluation.

Strategies to reduce your risk for stones

  • Healthy lifestyle (healthy diet and body weight, exercise, etc.)
  • Stay well hydrated (make sure your urine looks more clear than amber)
  • Consume citrate (high levels in citrus, particularly lemons), which is an inhibitor of stone formation
  • Avoid excess Vitamin C
  • Avoid high protein diets
  • Avoid excessive salt (kidneys tend to reabsorb sodium and compensate by excreting calcium in the urine)


Wishing you the best of health,

2014-04-23 20:16:29

A new blog is posted every week. To receive the blogs in the in box of your email go to the following link and click on “email subscription”:

Author of Male Pelvic Fitness: Optimizing Sexual and Urinary Health: available in e-book (Amazon Kindle, Apple iBooks, Barnes & Noble Nook, Kobo) and paperback: In the works is The Kegel Fix: Recharging Female Pelvic, Sexual and Urinary Health.

Co-creator of Private Gym, a comprehensive, interactive, FDA-registered follow-along male pelvic floor muscle training program. Built upon the foundational work of Dr. Arnold Kegel, Private Gym empowers men to increase pelvic floor muscle strength, tone, power, and endurance: or Amazon.

A Lemon A Day Keeps The Urologist Away

July 25, 2015

Andrew Siegel MD  July 25, 2015


The Northeast USA has recently experienced oppressively hot weather –sizzling, steaming, scorching, sultry hot. This extreme weather has the same significance to urologist as a frigid and icy winter to an orthopedist–a harbinger of busier office hours. Ice drives patients with fractures in to see their bone specialists, but heat drives patients with kidney stones in to see their urologists. Summer is the “high season” for kidney stones, often brought on by dehydration from the stifling heat. The hotter the temperature, the greater the prevalence of kidney stones. To help prevent this very common and extremely painful condition, it is important to stay well hydrated by drinking lots of fluids. A sign of good hydration is dilute-appearing urine, which looks more like lemonade as opposed to apple cider, or for the beer drinkers, light American beer versus a rich, dark European brew. Lemons, being citrus fruits, contain citrate in high concentration, a well-known inhibitor of kidney stones.

I’m puzzled why the word “lemon”—representing such a lovely fruit—is often used with negative connotations, referring to a poorly functioning car or a challenging situation that can be overcome, turning “lemon into lemonade.” I suppose it’s because of its natural tartness. But au contraire, the lemon is a citrus superstar that is appealing to all of the senses…to the eyes with its vibrant sunshine color and oval shape, to the nose with its distinctive citrus aroma and to the sense of touch with its firm, textured outer peel and juicy, segmented inner flesh and to the sense of taste, with its unique tart and acidic flavor.

Lemons are low calorie nutritional powerhouses.  In addition to citrate, lemons contain fiber, potassium, copper, calcium, flavonoids, B vitamins, folate and other phytochemicals. Lemons are packed with Vitamin C, a formidable anti-oxidant that helps slow oxidative damage that occurs via the accumulation of byproducts of metabolism and damage from environmental toxins. This accumulation is called reactive oxygen species (also known as free radicals) and contributes to diseases, aging and ultimately death.

Squeeze one-quarter or one-half of a fresh lemon into water or seltzer on the rocks for a refreshing, extremely low-calorie, delicious drink that is so much better for you than sweetened beverages such as sodas, fruit juices and sports drinks. This serves as a powerful tonic for preventing kidney stones. Urologists often prescribe medications containing citrate to help prevent stones, but why not try the natural, first-line approach at ramping up levels of citrate before trying the pharmaceutical approach?

In addition to being an awesome fruit that is great squeezed into a drink, lemon juice is wonderful on fish, in chicken dishes and in salad dressings. Lemons are often used as an ingredient for aromatherapy and in cleansing products as well. If you have ever visited Italy, particularly the Amalfi Coast region, you probably recall an abundance of citrus groves and a lemon-based liqueur called Limoncello available everywhere.

Bottom Line: If an apple a day keeps the doctor away, then a lemon a day keeps the urologist away! 

Wishing you the best of health,

2014-04-23 20:16:29

A new blog is posted every week. To receive the blogs in your email in box go to the following link and click on “email subscription”:

Obesity and Urology

April 5, 2013

Andrew Siegel, M.D.  Blog #101

A whopping two-thirds of adults in the USA are either overweight or obese.   In 1960 the obesity rate was 13%; currently it is 36%. Our physical activities have diminished, our stress levels and our portion sizes have increased, and our derrières have expanded accordingly.  There are an increasing abundance of readily available, unhealthy, processed, cheap foods.  These factors in sum have contributed to our weight gain and to a very negative impact on our overall health.  In addition to the more obvious increased risk for high cholesterol, high blood pressure, heart disease, stroke, and diabetes, weight gain and obesity are also associated with an increased incidence of gallstones, arthritis and other joint problems, sleep apnea and other breathing problems, as well as certain cancers. There are many other less obvious effects that obesity has, negatively impacting every system in our body.

Abdominal obesity—an accumulation of fat in our midsections—not only is unattractive from a cosmetic standpoint, but can have dire metabolic consequences that can affect the quality and quantity of our lives.  It is important to understand that fat is not merely the presence of excessive padding and insulation that signifies excessive intake of energy—but a metabolically active endocrine “organ” that does way more than just protrude from our abdomens, producing hormones and other chemical mediators that can have many detrimental effects on all systems of our body.  So, fat is not just fat. Today’s blog will focus on the harmful ramifications of weight gain and obesity on urological health. As a urologist, on a daily basis I sadly bear witness to the adverse effects and ill consequences of America’s bulging waistline.

Overactive bladder (OAB) is a common condition that causes urinary urgency, frequency, the need to run to the bathroom in a hurry, and at times urinary leakage before arrival at the bathroom. There is a clear-cut association between weight gain and the presence of OAB.   Similar to the way obesity taxes the joints, particularly the knees, so it burdens and puts pressure on pelvic organs including the urinary bladder.

Stress urinary incontinence (SUI) is a frequent ailment in adult women in which there is leakage of urine associated with a sudden increase in abdominal pressure, such as with sneezing, coughing, lifting, laughing, jumping, and any kind of strenuous exercise. Although the major risk factor is pregnancy, labor, and delivery, weight gain is clearly associated with exacerbating the problem.

Pelvic organ prolapse (POP) is a prevalent issue in adult women in which one or more of the pelvic organs—including the bladder, uterus, or rectum—drop down into the space of the vagina and possibly outside the vagina.  Similar in respect to stress urinary incontinence in that the major risk factor is pregnancy, labor and delivery, it is most certainly associated with weight gain and obesity, which have a negative effect on tissue strength and integrity.

Kidney stones are a major source of pain and disability and are very much associated with weight gain, obesity, and dietary indiscretion. Excessive protein and salt intake are unequivocal risk factors for the occurrence of kidney stones.   Uric acid stones, in particular, occur more commonly in overweight and obese people.  Beyond a certain weight limitation, “larger” patients cannot be treated with the standard, non-invasive shock wave lithotripsy to break up a kidney stone and urologists must, therefore, resort to more antiquated, more invasive, more risky measures.

Hypogonadism, a condition in which there are insufficient levels of the male sex hormone testosterone, is an increasingly prevalent condition that is associated with a host of negative effects. Obesity has a pivotal role in the process leading to low testosterone. One’s waist circumference is a reasonable proxy for low testosterone. Fat has an abundance of the hormone aromatase, which functions to convert testosterone to the female sex hormone estrogen.  The consequence of too much conversion of testosterone to estrogen is the potential for gynecomastia, a.k.a. “man boobs.”  Too much estrogen slows testosterone production and with less testosterone more abdominal obesity occurs and even more estrogen is made, a vicious cycle of emasculation and loss of libido.

Erectile dysfunction is a very prevalent condition associated with aging and numerous other risk factors. Weight gain and obesity are major contributors to poor quality rigidity and durability of erections.   This goes way beyond simply low testosterone levels.  Erections in essence are all about sufficient blood flow to the penis. Obesity contributes to problems with penile blood flow that can interfere in a major way with sexual function.   Additionally, as the abdominal fat pad grows, the penis seemingly shrinks and it is estimated that for every 35 pounds of weight gain, there is a 1-inch loss in apparent penile length. In fact, penile shrinkage is a very common complaint among my obese patients.

Prostate cancer is the most common cancer in men.  Like all cancers, prostate cancer is caused by mutations that occur during the process of cellular division.   Prostate cancer has a multifactorial basis, with both genetic and environmental factors at play. There is a clear association between a Western diet and the occurrence of prostate cancer.   This has been witnessed in Asian men, who have a relatively low incidence of prostate cancer in Asia, but after migrating to the USA and assuming a Western diet and lifestyle, have an incidence of prostate cancer that approaches that of Caucasians.

The obese patient presents a real challenge to the urological surgeon in terms of care both during and after an operation.  Surgery on overweight patients is more complex and takes longer as it is much more difficult to achieve proper exposure of the anatomical site being operated upon.  Surgery on obese patients has a higher complication rate with increased respiratory and wound problems. Anesthesiologists have more difficulty placing the breathing tube through a thick, obese neck, and greater difficulty with regional anesthesia as well, because of fatty tissue obscuring the landmarks to place the needle access for spinal anesthesia.

Bottom Line: Fat puts one at risk…for many very unfortunate potentialities.  Maintaining a healthy weight is an important priority for overall health, as well as our urological health.  The good news is that a lifestyle “remake” is typically the first line of treatment for many of the problems that I have just delved into and has the capacity of mitigating, if not reversing, some of them.  This involves the adoption of healthy eating habits, weight loss to achieve a healthy weight, and exercising on a regular basis.   

Andrew Siegel, M.D.

Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food:

Available on Amazon in paperback or Kindle edition

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Kidney Stones…Ouch!

October 19, 2012

Andrew Siegel, M.D.   Blog # 80


I have chosen kidney stones as a topic since they are a very prevalent problem that I treat on an everyday basis, and a condition often related to our dietary habits, the quantity of fluids that we drink, and our weight status.

If you have ever suffered with a kidney stone, you truly know what excruciating pain is.  Many women who have experienced both passage of a kidney stone and natural childbirth without any anesthesia will report that the childbirth was the less painful of the two!

Stones are a common condition that has occurred in humans since ancient times; kidney stones have even been found in an Egyptian mummy dated 7000 years old.   The good news about stones is that most of them will pass spontaneously without the necessity for surgical intervention. The other welcome news is that if surgery is required, it is minimally invasive—open surgery for kidney stones has virtually gone by the wayside.

Kidney stones form when minerals that are normally dissolved in the urine precipitate out of their dissolved state to form solid crystals. This crystal formation often occurs after meals or during periods of dehydration. The lion’s share of kidney stones manifest themselves during sleep, at a time of maximal dehydration.  Dehydration is also why kidney stones occur much more commonly during hot summer days than during the winter. This past summer—one of the hottest on record—kept urologists very busy in terms of caring for patients with kidney stones.   Anything that promotes dehydration can help bring upon a stone—including exercise, saunas, hot yoga, diarrhea, vomiting, being on bowel prep for colonoscopy, etc.

In addition to dehydration, another factor that can contribute to kidney stone formation is excessive intake of certain vitamins. The biggest culprit is Vitamin C, also known as ascorbic acid.   When metabolized by the body, Vitamin C is converted into oxalate, one of the components of calcium oxalate stones, the most common variety of stone.  The problem is that vitamin C is a water-soluble vitamin, so any excessive intake is not stored in the body but appears in the urine in the form of oxalate. Additionally, excessive dietary protein intake, fat intake, and sodium are all associated with an increased risk for kidney stones. Having inflammatory bowel disease or previous intestinal surgery can also increase the risk for stones.     Urinary infections with certain bacteria can promote stone formation. Having a parathyroid issue and high circulating calcium levels is another cause of kidney stones.  Obesity is also a risk factor for kidney stones. Some stones have a genetic basis, with a tendency to affect many family members.  My uncle is currently plagued with a stone lodged in his ureter and is scheduled for stone surgery on Monday, and both my father and brother have passed stones.  What does that bode for me?  So far I have been lucky.

A kidney stone starts out as a tiny sand particle that grows as the “grain” is bathed in urine that contains minerals.   These minerals are deposited and coalesce around the grain.  They can grow to a very variable extent so that when they start causing symptoms they may range from being only a few millimeters in diameter to filling the entire kidney.

Some stones are “silent” because they cause no symptoms and are discovered when imaging studies are done for other reasons.  However, most stones cause severe pain known as colic. Colicky pain is often intermittent, originating in the flank area and radiating down towards the groin.  It often causes an inability to get comfortable in any position, and is associated with sweating, nausea, and vomiting. Kidney stones can also cause blood in the urine, sometimes visible and, at other times, only on a microscopic basis. When a stone moves into the ureter (the tube running from the kidney to the bladder), it can become impacted and block the flow of urine. Stones can sometimes cause lower urinary tract symptoms such as urgency and frequency, particularly when the stone approaches the very terminal part of the ureter that is actually tunneled through the wall of the bladder.

Kidney stones are usually any easy diagnosis to make, based upon their rather classical presentation, although on occasion, a stone causes no symptoms whatsoever and is picked up incidentally on an imaging study such as an ultrasound, a CAT scan, or an MRI.   The imaging study of choice for evaluating a kidney stone is an unenhanced CAT scan (without contrast).   A plain x-ray of the abdomen is very useful for stones that contain calcium, and thus are readily visible on an x-ray.

Most stones will pass spontaneously without intervention given enough time.   Conservative management involves hydration, analgesics and the use of a class of medications known as alpha-blockers that can help facilitate stone passage by relaxing the ureteral smooth muscle.   As long as the pain is manageable and there is progressive movement of the stone seen on imaging studies, conservative management can continue to be an option.  Intervention is mandated under the following circumstances: intolerable pain; refractory nausea and vomiting with dehydration; larger stones that are not likely to pass; failure of a stone to pass after a reasonable amount of time; significant obstruction of the kidney; a high fever from a kidney infection that does not respond to antibiotics; a solitary kidney; and certain occupations that cannot risk impaired functions such as an airline pilot.

There are a number of minimally invasive means of treating kidney stones depending upon the size of the stone, its location, and the degree of obstruction of the urinary tract.  Gone are the days when treating a kidney stone required a painful incision and a prolonged stay in the hospital.  Most kidney stones now are managed on an ambulatory basis. Shockwave lithotripsy is commonly used to treat stones in the kidney or upper ureter.  Typically done under intravenous sedation, shockwave lithotripsy uses shockwaves directed at the kidney stone via x-ray guidance to fragment the stones into pieces that are small enough so that they then can then pass down the ureter, into the bladder and out the urethra with the act of urinating.  Another means of managing stones, particularly amenable to stones in the lower ureter but also applicable to any stone, is ureteroscopy and laser lithotripsy.  This procedure is done under general anesthesia. A narrow lighted instrument known as a ureteroscope is passed up the ureter to visualize the stone under direct vision.  A laser fiber is then utilized to break the stone into tiny particles.  The largest fragments are removed using a special basket. A ureteral stent is often left in place after this procedure to allow the ureter to heal as well as to prevent obstruction of the kidney.

You are at high risk for kidney stones if you:

  • Don’t drink enough fluids
  • Have an occupation that requires working in hot environments, such as a chef
  • Exercise strenuously without maintaining adequate hydration
  • Are a male, since the male to female ratio of kidney stone incidence is 3:1
  • Had a previous kidney stone, since about 50% of people who have a stone will experience a recurrence
  • Have a family history of kidney stones
  • Have a urinary tract obstruction
  • Have an excessive intake of oxalate, calcium, salt, protein and fat
  • Take excessive amounts of vitamin C, A, and D
  • Have an intestinal malabsorption
  • Have gout
  • Have parathyroid disease

The key to preventing kidney stones is to stay well hydrated, particularly when exposed to hot environments or when exercising for prolonged periods of time. It is also important to avoid overdoing it with certain vitamins—particularly vitamin C—a major risk factor for kidney stones.  The two biggest risk factors for kidney stones are, in fact, dehydration and excessive intake of vitamin C. Chances are that if you have a healthy diet, you have more than adequate intake of vitamin C and any extra is potentially dangerous. A good sign of adequate hydration is the color of your urine: the urine of a well-hydrated person will look light in color like lemonade, whereas the urine of a dehydrated person will look like apple juice.

So drink up, particularly on hot days…and eat an orange instead of popping a vitamin C supplement…your kidneys will thank you!

Andrew Siegel, M.D.

Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food:

Available on Amazon in paperback or Kindle edition

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For a nice booklet on kidney stones in PDF, go to and click on patient education and then on ABCs of Kidney Stones