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Renal Calculus (I’m not talking about Math)

There’s coming to work sick, and then there’s coming to work with a kidney stone.

I was reminiscing earlier today about that time when I won a major gymnastic championship while I was suffering from a kidney stone, and — oh WAIT THAT WASN’T ME IT WAS SIMONE BILES, Olympic gymnast.

Did you hear about that? Incredible.

Fortunately, kidney stones aren’t all that common in children, but ask anyone, kid or adult, who has had one and they will tell you that the pain is an order of magnitude beyond pretty much anything you’ve ever imagined.

Kids CAN get kidney stones, though, so it seems timely to bring up the topic. First, the name. Kidney stones are a good descriptor and an accurate lay term, but the medical names are renal calculus (25 cents, plural renal calculi) or nephrolithiasis. Snazzy, right? You might be able to impress a few folks by trotting those words out in casual conversation, so keep that in mind. Renal calculi occur in a variety of situations, most commonly when there’s an underlying disorder that predisposes a child to getting them. Certain metabolic or genetic diseases, urinary tract defects, specific medicines, and even plain old dehydration are all culprits.

One thing I find interesting about kidney stones is that there are varying types of compounds that can crystallize in the urine to comprise them. Here are a few:

  1. Uric Acid. This compound can make a stone on its own or when combined with calcium.
  2. The most common type of calculus, calcium can combine with several other substances to form stones.
  3. This is an amino acid, and stones occur when there’s too much of this in the urine.
  4. These are also called “staghorn calculi” because of their shape (like antlers), and this compound becomes a stone most often in the setting of infection.

types of kidney stones


Most everyone knows that kidney stones are painful, most commonly in the back or side, but in addition kidney stones can cause other symptoms, too. Blood in the urine and frequent urination occur as well, and the pain is typically described as coming in waves or on and off, ranging from a dull ache to completely debilitating. People with kidney stone pain, called “renal colic,” are often described as unable to stay still and get in any comfortable position. The degree of pain often depends on the size of the stone and location in the urinary system. The larger the stone, the more painful, especially if it is located in a narrow urinary tube. Nausea and vomiting are also frequently associated with kidney stones. Sounds 100% crummy, right? I still cannot believe Simone Biles powered through a gymnastics competition with one of these, even if she got some medicine for pain. Not easy


Kidney stones are typically diagnosed by checking the urine and getting some radiology imaging. The urinalysis often shows blood and sometimes even the crystals themselves. Other tests like ultrasound or a fancy spiral CT scan can detect stones and determine their location, which is helpful when deciding on treatment.

image of signs of kidney stone (fever, blood in urine, painful urination) and risks (genetic, overweight, medications, foods, dehyderation)


Small stones can be managed at home with hydration, urine straining (like with a colander), and pain medicine, but larger calculi require hospitalization for pain management and rehydration, and even special procedures to break the stone up using sound waves, or even invasive procedures if that doesn’t work.

Aside from being miserable and NOT winning whatever is your or your child’s equivalent of a major gymnastics competition, not treating kidney stones in a timely manner can lead to significant compromise of kidney function and permanent kidney damage, so it’s critical to consider this diagnosis whenever there’s significant back or side pain, especially if it’s episodic  (renal colic), and bloody urine. While it certainly is fairly uncommon in generally healthy children, it can happen in situations where a child has gotten dehydrated along with eating a poor diet. Quick recognition and management is the best bet for both pain relief and decreasing any chances of kidney injury, so keep Simone Biles in your head when you hear someone complaining that their side is killing them all of a sudden.

In a situation like this I suggest seeking immediate emergency care and not finishing your second vault attempt or even sticking around for the floor exercise.