Kidney Stones: A Quick Overview

Chances are either you or someone you know has experienced kidney stones. While these pesky stones are usually small enough to be excreted through your urine, larger stones may require more medical attention. Here’s what you need to know about kidney stones and how to prevent them.

What are Kidney Stones?

Kidney Stones form when high levels of mineral salts crystallize in the urine. Typically, mineral salts dissolve in the urine and are excreted as waste. However, when the urine becomes too saturated with these salts, they cannot dissolve, leading to crystallization and stone formation. Kidney stones consist of calcium, cystine, uric acid, or struvite.

Kidney stones usually form in the kidneys but can develop anywhere along the urinary tract. Once formed, they either stay in the kidney or move down the ureter tract towards the bladder and urethra.

Risk Factors of Kidney Stones

Kidney stones are more common in men than in women (1). They are likely to peak between the ages of 20-30 years but can develop at any age (2). Kidney stones are significantly more common in people with kidney disease. In fact, an estimated 20-30% of people with polycystic kidney disease (PKD) develop kidney stones compared to only 1% of the general population (3).

Other common risk factors include:

• Low urine volume
• Previous stone formation
• High calcium levels in the urine
• High uric acid levels in the urine
• High oxalate levels in the urine

Low urine output caused by dehydration is considered one of the most significant risk factors associated with the development of kidney stones (4).

What are the Symptoms of Kidney Stones?

Kidney stones usually don’t cause any symptoms until they move out of the kidney to the ureter, causing a blockage of urine flow. The discomfort or pain associated with the kidney stone will travel depending on the location of the stone within the urinary tract system.

Other symptoms include:

• Hematuria (blood in the urine)
• Nausea and vomiting
• Painful urination
• Urgency to urinate

How are Kidney Stones Diagnosed?

If you believe you may have a kidney stone, it’s important to see your doctor. Diagnosis of a kidney stone involves capturing images of the kidneys, bladder, and ureter with x-ray or ultrasound technology. Additionally, urine and blood are usually analyzed to check for factors that may contribute to kidney stones.

Treatment:

Treatment of a kidney stone depends on if the stone can be passed through the urine. Stones expected to pass on their own call for drinking additional fluids and taking pain medication.

A kidney stone that’s too large to pass, is blocking urine flow, or is causing an infection may require a medical procedure to be removed.

• ESWL (extracorporeal shock wave lithotripsy) is a non-invasive treatment that uses shock waves to break stones down, so they can pass in the urine.
• Percutaneous nephrolithotomy and ureteroscopy are minimally invasive treatments that involve surgically removing the stone.

Prevention:

Prevention of kidney stones generally comes down to hydration and making smart food choices.

• Drink plenty of water throughout the day to ensure your urine doesn’t become too concentrated with mineral salts.
• Eat enough calcium-rich foods like bok choy and broccoli
• Limit intakes of food high in sodium
• Reduce your intake of high oxalate foods like beets, spinach, rhubarb, nuts, chocolate, and dried beans to prevent calcium stones.
• Reduce your intake of high-purine foods like meat, seafood, and gravy to prevent uric acid stones.

Nobody wants to experience the pain that can be associated with kidney stones. Drinking plenty of water, reducing meat intake, and increasing vegetable consumption may reduce your chances of developing stones. If you experience symptoms associated with kidney stones, see your doctor to discuss the best treatment options.