Kidney stone disease (nephrolithiasis) is a common problem that sometimes presents in different ways. Some patients may only experience symptoms such as back pain and blood in the urine (hematuria), while others may have no symptoms at all or experience more classic symptoms, such as severe flank or abdominal pain, nausea, urinary urgency or frequency, difficulty urinating, or testicular pain.
Diagnosing and evaluating a patient with symptomatic or suspected Kidney Stones involves a thorough Medical History, Urinalysis, Blood Tests, Diagnostic Imaging, and Stone Analysis. Monitoring a patient for recurrent stones is a key part of the diagnostic process.
Diagnostic Approach
Dr. Steinberg’s diagnostic approach is to identify and understand a patient’s physiologic and behavioral factors to treat and prevent recurrent kidney stones. The diagnostic process is shaped by the severity and type of kidney stone, whether the kidney stone is recurrent, and other Risk factors such as diet and medication.
Medical History
A complete medical history focuses on identifying risk factors for stone risk disease, such as a family history of stone disease, recurrent stones, medications,and dietary habits.
These dietary habits may pose an increased risk of developing kidney stones:
- Low fluid intake or a high fluid loss, such as from sweating
- High animal protein diet
- High sodium diet
- Increased intake of high oxalate-containing foods, such as spinach.
- Low calcium diet
- Excessive Vitamin C and Vitamin D supplements
- Excessive sugar (sucrose and fructose)
- Lack of citrate in diet, typically found in citrus fruits and juices
Urinalysis
A urinalysis should be performed in the office as part of the kidney stone evaluation. Analysis of the urine sample will detect if there is any blood in your urine or minerals that can cause certain types of kidney stones to grow. Determining pH levels is also important as a pH level greater than 7.5 raises the possibility of a stone due to urease-producing bacteria, whereas a pH level less than 5.5 favors a stone due to uric acid.
In addition, Urinalysis allows urine to be examined for crystals, since certain crystal types may provide insight as to the composition of the kidney stone.
Blood Tests
Dr. Steinberg typically orders blood tests to measure the presence of several minerals, such as calcium, phosphate and uric acid, that are likely to be related to kidney stone formation. Blood tests can also be used to evaluate how well the kidneys are functioning in a patient with kidney stones.
Radiologic Testing
Radiologic imaging tests are frequently used to diagnose kidney stones. The images show if a kidney stone is present, and can also help determine the location, size and shape of the stone.
- Ultrasound for Kidney Stones
- Dr. Steinberg usually recommends an ultrasound for kidney stones because it is a painless, quick, safe procedure that is performed in our office by an experienced sonographer. An ultrasound uses sound waves to create images and does not expose a patient to radiation. These images provide pictures of the kidneys and bladder, and can reveal blockage of urinary flow and help identify stones.
- In most cases, an ultrasound provides enough evidence to confirm the presence of a kidney stone. However, in some cases, the images do not provide enough information. In these instances, Dr. Steinberg may order a computer tomography (CT) Scan to further diagnose the size, location and number of stones in order plan your treatment.
- X-Ray for Kidney Stones
- An X-Ray of the kidneys, ureters and bladder (KUB) may be recommended to look for large kidney stones or the presence of many stones.
- Computed Tomography (CT) Scan for Kidney Stones
- According to the American Urological Association, the current gold standard for confirming kidney stones is a non-contrast CT of the abdomen and pelvis. A CT Scan for kidney stones can detect tiny pieces that other imaging tests might miss, as well as show the size of the stone, its location, and if there are any urinary blockages. A CT scan uses x-ray beams to capture images from different angles. A computer processes the information and produces three-dimensional pictures of the area scanned.
- Because a CT Scan involves multiple x-ray images, CT scans involve exposure to low levels of radiation. While a single CT Scan is considered safe for most people, repeated CT scans would expose patients to increased radiation.
- Because a CT Scan involves multiple x-ray images, CT scans involve exposure to low levels of radiation. While a single CT Scan is considered safe for most people, repeated CT scans would expose patients to increased radiation.
Stone Analysis
Dr. Steinberg believes that understanding the composition of the kidney stone is essential to the diagnosis and evaluation of kidney stones. He encourages patients who pass stones on their own to retrieve the stone for analysis. Similarly, stones that are surgically removed are submitted for analysis. Knowledge of the composition of the stone assists with the treatment plan decisions for the existing stone as well as recommendations for the prevention of new stone formation.
The most common components found in kidney stones are:
- Calcium Oxalate
- Calcium oxalate is the most common component found in kidney stones. Approximatel 70 to 80 percent of kidney stones are composed of this material
- Calcium Phosphate
- Calcium phosphate is found in approximately 15 percent of kidney stones and can be present in combination with calcium oxalate or struvite
- Uric Acid
- Uric acid is present in approximately 8 percent of analyzed stones, sometimes in combination with calcium oxalate. These stones are more common in patients with gout.
- Struvite
- Struvite is found in approximately 1 percent of analyzed stones. Struvite stones form only in the presence of urease-producing bacteria that are in the upper urinary tract and is more common in females than in males due to the higher risk of urinary tract infections in females.
Monitoring For New Stones
According to a study by the NIH, 60%-80% of patients who have had one kidney stone will have a recurrence during their lifetime.
Dr. Steinberg closely monitors patients who have had kidney stones. Periodic radiology testing, typically ultrasound, is used to proactively monitor old stones and identify recurrent stones.
Depending on the composition of the stone, Dr. Steinberg may order a 24-hour Urine Collection test to assess your urine composition in order to effectively manage and prevent additional kidney stones.
We routinely utilize the convenient Litholink At-Home 24-Hour Urine Collection Test Kit, which is delivered to your home and picked up after completion of the urine collection.
Dr. Steinberg reviews the results of all diagnostic tests with you and provides detailed recommendations for a preventive regimen, including any dietary changes, medications or supplements to help prevent future recurrent kidney stones.
Learn more about how LithoLink may help you manage and prevent further kidney stone here.
Harvard-trained and Board-certified urologist Dr. Jeffrey Steinberg has more than 30 years of experience helping patients manage and prevent kidney stone disease. To request a consult with Dr. Steinberg, contact Urology Specialists of Milford at (508) 473-6333 to schedule an appointment in our Milford, MA office.
