Kidney Stones

Kidney stones

Kidney stones are deposits of mineral salts that develop in the kidney due to a variety of factors.  They are a common problem afflicting approximately 10% of the U.S. population.  Virginia is part of the “stone belt” which encompasses the southeast making stones more common in our state.

Causes

The most common cause for kidney stones is dehydration.  Dietary factors, metabolic disorders, urinary tract infection and anatomic abnormalities can have an influence as well.

Symptoms

Kidney stones cause pain when they begin to obstruct the outflow of urine from the kidney.  Non-obstructing (remain in the kidney) stones usually do not cause pain however they can cause a dull ache located over the affected kidney.  Often non-obstructing stones can lead to blood in the urine.  Kidney stone pain is most severe when the stones move into the ureter or tube connecting the kidney to the bladder.  Kidney stone pain usually begins in the flank and then can radiate around to the abdomen and groin.  The pain usually comes in waves: rising and subsiding.  Obstructing stones in conjunction with a urinary tract infection are medical emergencies and can present with high fever, chills, body aches as well flank pain.

Diagnosis

Symptom history and description are important, but x-ray, ultrasound and CT scan are the best methods for diagnosing kidney stones. X-ray is the quickest, but CT scan is the most definitive.  Findings of blood in the urine or under microscopic exam of the urine can be suggestive of stones but can also be present with other conditions.

Treatment

A variety of options are available for treatment of kidney stones and the method used depends on the stone location and size.  The majority are minimally invasive or endoscopic and can be performed on an outpatient basis.

FAQ

Q: What is the best way to prevent kidney stones?

A: Hydration.  The American Urological Association recommends that recurrent stone formers drink enough fluids in a day to produce 2.5L of urine per day.  This is a lofty goal and would keep you in the bathroom for most of the day. However, it should be a reminder that you probably need to drink more water than you already are during the day if you have previously had a kidney stone.  Consult your doctor before significantly adjusting your fluid intake as this may influence other medical conditions.

Q: What changes can I make to my diet to avoid making kidney stones?

A: A low sodium, low non-dairy animal protein, high fruit & vegetable, and low oxalate diet is recommended to prevent the most common type of stone seen in the U.S. (calcium oxalate).   A list of high oxalate containing foods can be found here:

https://kidneystones.uchicago.edu/how-to-eat-a-low-oxalate-diet/

Q: Do vitamins and minerals play a role in kidney stone formation?

A: Absolutely.  A common misconception is that since most stones are made of calcium, then limiting calcium intake will be beneficial.  This is not necessarily true.  In fact, not consuming enough calcium may increase the risk of kidney stone formation.  Consumption of about 1000mg of calcium of day is recommended unless directed otherwise by your physician.  Excessive vitamin C is converted to oxalate so don’t over-supplement unless instructed by your doctor.