Most people don’t realize this, but 10-15% of all Americans develop kidney stones at some point in their lives. The condition, known medically as renal stones or nephrolithiasis, occurs when people’s urine has higher-than-usual levels of minerals and salt, starting out small and all but unnoticeable and growing in size until they cause more serious problems.
What Are Renal Stones?
Renal stones form when the concentrations of certain minerals in patients’ urine become too high. The minerals form crystals, which grow over time to create renal stones. Some renal stones are small and pass through the kidneys, ureter, and bladder to be expelled with regular urination without much fanfare. Others grow large enough that they cause patients significant pain and may even wind up blocking their ureters.
Types of Renal Stones
There are four main types of renal stones, each of which contains different minerals. Both treatment and prevention guidelines vary based on the type of stones patients have, so identifying the crystalline minerals is often the first step toward coming up with an effective plan.
Calcium stones are the most common form of renal stone, accounting for around 80% of all diagnosed cases. They come in two varieties: calcium phosphate and calcium oxalate. Calcium oxalate stones are far more common. Most calcium renal stones form as a result of excess calcium levels in urine, but there are other risk factors for developing this form of nephrolithiasis, as well.
Uric Acid Stones
Uric acid stones aren’t as common as calcium stones, comprising only 5-10% of diagnosed cases. They occur when uric acid, a waste product created by the body and normally expelled through urine, starts to build up and form crystals. The primary risk factor for developing uric acid stones is acidic urine resulting from chronic diarrhea, obesity, high blood sugar, gout, or a high-protein, low-fiber diet.
Struvite stones, also known as infection stones, occur in about 10% of patients diagnosed with nephrolithiasis. People who experience frequent or chronic urinary tract infections are at high risk for developing infection stones, which occur when urine becomes too alkaline. Struvite stones grow faster than other types of renal stones and can even form branches, making them difficult to pass naturally.
Cystine stones are exceedingly rare. They account for less than one percent of all renal stones and only occur in patients suffering from cystinuria, a rare inherited condition that causes patients to have too much cystine in their urine. If the kidneys cannot reabsorb sufficient amounts of it, the leftover cystine creates stones. Cystine renal stones most frequently occur for the first time during childhood.
Causes of Renal Stones
As has already been made clear, each type of renal stone has a different mineral composition. Risk factors for developing different forms of renal stones also vary. There are a few underlying conditions and lifestyle factors that can increase anyone’s risk of developing one or more forms of renal stones. They include:
- Consistently low urine volume
- Excess salt, oxalate, or animal protein intake
- Underlying bowel conditions like Crohn’s Disease and ulcerative colitis
- Recent gastric bypass surgery
- Abnormal growth of parathyroid glands
- Distal renal tubular acidosis
- Inherited conditions like cystinuria and primary hyperoxaluria
- Taking certain medications or supplements like calcium and vitamin C
- A family history of kidney stones
Preventing Renal Stones
Once healthcare providers determine what kinds of stones patients are forming and what is causing them, the doctors can make recommendations about how to prevent future problems. There’s no one-size-fits-all approach to preventing renal stones. For some patients, dietary changes may be enough to reduce risk. For others, medication interventions are a better fit.
Patients with low urine volume often need to increase fluid consumption. Around three liters of fluid is a good benchmark. Urologists may also recommend reducing salt, calcium, oxalate, or protein intakes and increasing the number of fruits and veggies in a patient’s daily diet.
Medications and Supplements
Dietary changes alone may not be able to prevent renal stone formation. Some patients can also benefit from certain medications depending on what risk factors they have and what kinds of stones they are forming. Common medications for preventing renal stone formation include:
- Thiazide diuretics
- Potassium citrate
- Acetohydroxamic acid
- Cystine-binding thiol medications
- Certain over-the-counter nutritional supplements
Treatment for Renal Stones
Small renal stones may eventually pass by themselves. It’s generally safe to wait up to six weeks for a stone to pass, provided the pain is not unbearable and there are no signs of blockage or infections. Patients with larger renal stones, infections, or blockages have a few treatment options.
Medications like tamsulosin relax the ureter, increasing the likelihood that patients will be able to pass smaller kidney stones. Doctors may also prescribe pain and anti-nausea medications in the intervening time.
Shock Wave Lithotripsy (SWL)
SWL can be used to treat renal stones in the kidney or ureter. It involves focusing shock waves on the stone using an ultrasound or X-ray machine, causing the stone to break into smaller pieces that are easier to pass. SWL isn’t appropriate for hard stones or very large stones.
URS involves passing a ureteroscope into the bladder, ureter, or kidney, allowing the doctor to see and more easily remove smaller stones. Large stones can be broken into pieces prior to removal.
Percutaneous Nephrolithotomy (PCNL)
PCNL is the most effective treatment for larger renal stones. This surgical procedure involves making a small incision in the patient’s back or side to allow the insertion of a nephroscope into the kidney. Once the doctor has found the stones, he or she can break them up and suction out the pieces.
Get Help Now
Suffering from renal stones in South Carolina? Don’t put off getting treatment. The experts at Atlantic Urology Clinics are taking new patients. They can diagnose any form of renal stones, prescribe treatment, and help patients come up with a plan for avoiding future recurrences.