Kidney stones (also known as nephrolithiasis) form when common urine substances build up, crystallize and harden into stone-like deposits.
The most common stones are composed of calcium oxalate, calcium phosphate, uric acid, or struvite. Kidney stones are very common in the United States. The most common stone symptom is flank pain caused by a blockage in the flow of urine to the bladder. About 1 in 10 people experience kidney stones, and about 50% of people have another stone episode within 10 years of the initial event. Management of your kidney stones will be personalized based on size and the location of stones. Although certain types of kidney stones may be treated with medications, the vast majority require a procedure for removal. Not all kidney stones require immediate treatment however, and some may be observed if asymptomatic and located in the kidney.
Causes and Risk Factors
Stone disease is a chronic medical condition affected by multiple risk factors that include:
- Increasing age
- Male gender
- Family history of kidney stones
- Hot weather
- Poor fluid intake
- Diet rich with animal proteins
- Chronic urinary tract infections
- Anatomic abnormalities of the urinary system
- Genetic conditions that affect mineral metabolism in the urine
- Certain surgeries such as gastric bypass
- Certain digestive disorders such as Crohn’s Disease
When to Speak with a Urologist about Kidney Stones
You should talk to a Urologist about kidney stones if you or your primary care doctor suspect you have stones based on symptoms such as flank pain or blood in the urine or based on imaging results. If you have severe pain with fevers, chills, or persistent vomiting, you should seek care immediately at an Emergency Room for possible inpatient evaluation by a Urologist.
What to Expect when Seeking Treatment
In addition to a history and physical examination, the initial assessment typically includes urine testing to rule out infection and blood work to assess renal function and mineral levels. Imaging with non-contrast CT scan of the abdomen and pelvis should be obtained in order to delineate the number and location of the stones as well as to determine the anatomy and inform the most appropriate surgical approach. Sometimes imaging can be with renal and bladder ultrasound and abdominal x-ray. Any stone fragments that have passed spontaneously can be sent for mineral testing to understand the specific type of stone present. Additional metabolic testing may include completion of a 24-hour urine study to precisely determine and identify mineral abnormalities in the urine.