BHUBANESWAR: Ipsita Singh was experiencing recurring back pain, and multiple visits to an orthopedician did not show any visible improvement even after a couple of months of treatment. The 45-year-old banker was evaluated by multiple doctors, but they were unable to diagnose her problem correctly. However, an ultrasound of her abdomen followed by a CT scan revealed two large stones in her kidney that were not visible on a conventional X-ray.
The stones were removed with laser surgery, and with that, her back pain vanished. Kidney stones (or urolithiasis) are becoming increasingly prevalent in India. Epidemiological studies show that the prevalence of kidney stones in the country is about 12%, with more men being affected than women. It is relatively more common in the northern states of India, where the prevalence rate is 15% or higher.
Dr Samir Swain, head of urology at SCB Medical College and Hospital, Cuttack, said north India reports more renal stone cases due to the hot and arid climate, while coastal states have a relatively lower prevalence. "It is more prevalent in states like Maharashtra, Punjab, Gujarat, Rajasthan, Tamil Nadu, Andhra Pradesh, and Telangana.
Men are more affected than women, and the condition tends to peak between the ages of 20 and 50 years. The rising incidence is linked to lifestyle changes such as increased consumption of a high-sodium diet, dehydration due to hot climate, and urbanisation," he said. As the factors behind kidney stones are multifarious, the chances of recurrence are high regardless of treatment.
Around 98% of patients may develop another stone within 25 years of the first episode. The most common types of stones are calcium oxalate, calcium phosphate, uric acid, and struvite, in addition to cystine stones. Calcium oxalate stones are the most common, accounting for about 70% of all kidney stones.
Causes and symptoms
Although there are no specific causes, experts note that genetic polymorphism of vitamin D receptor (VDR), klotho, and Chloride Voltage-Gated Channel (CLCN) genes play a significant role in the formation of kidney stones. These genes can influence kidney stone risk by affecting calcium and phosphate balance, urine composition, and kidney function.
These genetic factors increase susceptibility, while lifestyle, dietary preferences (such as a diet high in animal protein), and hydration levels help determine whether a person with genetic predispositions will develop kidney stones. “Many times, patients do not manifest the typical symptoms of stone disease, making the diagnosis difficult,” said Dr Manas Ranjan Pradhan, senior consultant of urology at Manipal Hospitals, Bhubaneswar. The stones form when minerals and salts in urine crystallize and harden into solid deposits. Some individuals inherit a predisposition to form kidney stones due to disorders such as cystinuria or hyperoxaluria.
"Medical conditions like hyperparathyroidism also increase calcium levels in the blood and urine. Similarly, gout leads to higher uric acid levels, and obesity alters urinary pH, increasing the risk of both calcium and uric acid stones. Besides, medications such as diuretics, calcium-based antacids, and protease inhibitors are also known to increase stone formation risk," said Dr Swain. Exposure to heavy metals such as cadmium and lead through cigarette smoke or contaminated food and water can cause renal stones to form through crystallization in urine and crystal induction. Pain is the most common symptom, felt in the abdomen or back. It is typically severe and episodic, often accompanied by vomiting. Blood in the urine, sudden stoppage of urine flow, and fever may also be present in many patients. If left untreated, kidney stones can lead to kidney failure and may be fatal in some cases.
"Patients should be aware of intense flank pain, known as renal colic, which often radiates from the back to the lower abdomen and groin as the stone travels through the urinary tract. Apart from hematuria (blood in urine) due to irritation caused by stones passing through the ureter and cloudy or foul-smelling urine, patients also report nausea and vomiting triggered by severe pain. Stones in the lower ureter or bladder may cause frequent and urgent urination. Some may develop fever and chills, indicating pyelonephritis, a serious kidney infection," said Dr Swain.
Diagnosis
Diagnosis of stone disease is straightforward, with ultrasound being the first and most common method of investigation. However, a CT scan provides the best and most accurate information. Sometimes, other ancillary tests, such as an X-ray of the kidney, ureter, and bladder, intravenous pyelogram (IVP), and urine analysis, can also reveal the condition.
Advanced diagnostic methods like ultrasonography and CT scans are crucial for effective treatment. "Ultrasound enables healthcare professionals to visualise stones without the risk of exposure to radiation. This method is especially beneficial for pregnant women, children, and individuals requiring frequent assessments. CT scans are considered the gold standard for detecting kidney stones.
They can rapidly identify even small stones and evaluate their precise location, size, and any possible blockages within the urinary tract," said Dr Akila V., consultant nephrology and transplant surgeon at Aster CMI Hospital, Bengaluru. Additionally, a 24-hour urine analysis can measure levels of calcium, oxalate, citrate, and uric acid to assess risk factors for stone formation, while a dipstick test can quickly identify hematuria, urine pH, and signs of infection. Certain blood tests can also indicate levels of calcium, phosphate, uric acid, and renal function markers to identify metabolic disorders that may contribute to stone formation.
Treatment and complications
Treatment of kidney stones is usually surgical, barring very selective cases. Contrary to popular belief, medicines cannot dissolve kidney stones. While small stones (less than 5mm) often pass on their own without treatment, those lodged in the ureter (the narrow tube carrying urine from the kidney to the urinary bladder) may pass with the aid of medications. Procedures have become minimally invasive and are no longer open surgeries.
The use of laser technology in urology has revolutionised the treatment of renal stones. Previously, long abdominal incisions were required to remove the stones. “With the advent of sophisticated instruments, treatment has become faster, cheaper, and painless. Now, all stones can be removed through the natural urinary passage or through a tiny hole made in the back. Stones in the kidney and ureter are finely dusted using laser energy and are flushed out through the natural urinary passage. Very large kidney stones are broken into smaller fragments and taken out through a small hole made into the kidney at the back," said Dr Pradhan.
Extracorporeal shock wave lithotripsy (ESWL) is another non-invasive procedure that uses high-energy shock waves to break stones into small pieces. No real surgery is required, reducing hospital stays to just a few hours. The small stone fragments are gradually cleared through urine, he added.
Dr Akila explained that medications are commonly used to alleviate pain, with analgesics prescribed to ease discomfort and alpha-blockers to relax the urethral muscles, promoting stone passage. Though ESWL and minimally invasive surgeries are most preferred, percutaneous nephrolithotomy (PCNL) is performed for larger stones. This procedure involves a small incision in the back to extract stones directly from the kidney, she said. Untreated stones can lead to a variety of complications and significant suffering.
They may cause kidney infections that could be fatal and may damage the kidneys, leading to renal failure and the potential need for dialysis or a kidney transplant. "If a stone is stuck in the ureter, it can block urine flow, leading to hydronephrosis (swelling of kidney) and permanent kidney damage. Obstructed urine flow increases the risk of urinary tract infections. Untreated stones can also cause progressive kidney damage, contributing to chronic kidney disease and eventually kidney failure," Dr Swain added.
Prevention
Kidney stones are known for their tendency to recur. Half of the patients with the disease may experience stone formation again in the future. Because the cause of recurrent stone formation is not always known, it is challenging to prevent stones entirely.
However, dietary modifications, lifestyle changes, regular yoga with physical exercise, and increased water intake can help prevent stone formation. Reducing the intake of animal protein, weight loss in obese patients, and consuming more citrus fruits are also beneficial. Contrary to popular belief, calcium intake does not increase the risk of stone formation and should not be discontinued in patients with stones. "People should drink at least 2-3 liters of water per day to dilute urine effectively and prevent stone formation. Reducing the intake of sodium and oxalate-rich foods such as spinach, beetroot, nuts, and chocolate is also advised. A moderate intake of dietary calcium (1,000-1,200 mg per day) can reduce stone risk by binding with oxalate in the gut. Patients with recurrent stones or specific metabolic disorders may be prescribed preventive medications, such as thiazides, or allopurinol, based on the stone type," Dr Swain added.
(With inputs from Rishita Khanna @ Bengaluru)