Kidney stones are also known as renal calculi or urolithiasis. They are crystal concretions formed typically in the kidney. The most common causes of kidney stones are low fluid intake, dietary factors, hot climate, urinary tract infections, and certain medical conditions like diabetes, obesity, gout, and hypertension.
Urine contains different dissolved minerals and salts. When these minerals and salts are present in high concentration, stone formation in the kidney takes place. Kidney stones range from small to large in size, enough to fill the inner hollow structure (pelvicalyceal system) of the kidney. Some stones remain inside the kidney, while others may travel down the ureter, in the tube between the kidney and the bladder. The stone, when it reaches the bladder, may be passed out of the body in the form of urine. If the stones get lodged in the ureter, it blocks urine flow from the kidney and causes pain.
Prevalence of Kidney Stones
Urolithiasis affects about 12% of the world population in their lifetime. It affects all ages, sexes, and races but occurs more frequently in men (11%) than in women (9%) within the age of 20–49 years. The recurrence rate of urolithiasis is estimated to be 10–23% per year, 50% in 5–10 years, and 75% in 20 years and it is higher in males, although the incidence of urolithiasis is increasing in females.
Common types of Kidney Stones
Kidney stones show variations as they are composed of different elements. Some of them are mentioned below:
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Calcium Stones
These are the most common kind of kidney stones, accounting for nearly 80% of all kidney stones. It is further classified as calcium oxalate and calcium phosphate.
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Uric Acid Stones
They are waste products formed from chemical changes within the body. The crystal of uric acid does not dissolve in the acidic urine, thus forming uric acid stones.
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Struvite or Infection Stones
These kidney stones account for around 5% and are usually formed during chronic urinary tract infections secondary to diabetes, and neurological disorders. The presence of bacteria makes the urine less acidic and more alkaline. The alkaline urine results in the formation of magnesium ammonium phosphate, which is the struvite stone.
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Cysteine Stones
Cysteine stones are relatively uncommon compared with other stone compositions, constituting just 1% to 2% of adult urinary tract stone diseases, and accounting for up to 10% of pediatric stone diseases.
Symptoms of Kidney Stones
The common symptoms associated with kidney stones, including acute pain radiating from the loin to the groin, occurs once the stone begins descending the ureters from the kidneys. It is often described as dull, colicky, sharp, and severe pain. The pain is often associated with nausea and vomiting due to the severity of the pain. Hematuria (blood in the urine) is commonly reported as well. Go visit a Nephrologist in Mangalore if you are feeling any of the symptoms.
If the stone becomes infected, patients may develop fever, chills, or other signs of worsening systemic signs of infection. This situation can be difficult and life-threatening, requiring emergency surgery.
Diagnosis of Kidney Stones
The healthcare providers examine the medical history of the patient and conduct a physical examination. Some of the common diagnostic tests for kidney stones include:
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Blood Test
Blood tests to assess renal function (Blood Urea and Serum Creatinine), including either a basic or comprehensive metabolic panel, may be used.
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Urine Test
This test helps in determining any specific signs of infection and examining the level of substances forming kidney stones.
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Imaging Test
X-ray KUB (kidney, ureter, and bladder ) can be obtained to screen for the presence of significant nephrolithiasis but may often miss stones that are small, hidden by the bowel, or uncalcified. Ultrasound may be very useful for assessing obstruction and resultant hydronephrosis, especially in pregnancy where X-ray studies are discouraged.
However, some stones like uric acid stones are not visible on X-ray KUB then CT KUB without contrast is done to diagnose.
Treatment and Management of Kidney Stones
Medical or surgery is advised based on the location and size of the stones and whether the infection is present or not.
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Medications
Initially, Medications are given to decrease pain, manage nausea and vomiting, and may help pass out the small stone (< 5mm) in the ureter and kidney. But if medical therapy fails and in a large stone with an infected system, surgery is the treatment of choice. To know more, book an appointment at our Nephrology Hospital in Mangalore.
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Surgery
Based on Stone's size and location different surgical options are there.
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ESWL - Shockwave lithotripsy is used in small stones less than 1-2 cm with a variable stone clearance rate.
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Minimal Invasive surgeries like URSL/ Flexi URS and LASER surgery and PCNL/ miniPCNL (Keyhole surgery).
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Open surgery is very rarely done nowadays.
Complications due to Kidney Stones
Several complications can arise due to kidney stones, and subsequently, stones that cause obstruction. These include:
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Acute Kidney Injury(AKI) - Decrease in Kidney function.
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Infection (Urosepsis)
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Loss of kidney function may require temporary/permanent dialysis.
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Very rarely patients can develop tumors.
Consultant - Urology
KMC Hospital, Mangalore
