Kidney stones Kidney stones are a common disease in urology, with an incidence rate in the Western world ranging from 0.1% to 14.8%, and in China, the incidence rate is between 1.61% and 20.54%. It is more common in males, with a higher incidence in the 30-50 age group. In China, it is more common in the southern regions than in the northern regions, and the incidence is significantly higher in the summer than in other seasons. Studies have shown that with the gradual warming of the global climate, the incidence of human kidney stones is also gradually increasing.

Kidney stones are formed within the kidneys from certain components in the urine, leading to a series of urinary system symptoms in patients. Kidney stones are a common condition in urology, with a prevalence of approximately 0.1% to 14.8% in Western populations and 1.61% to 20.54% in China. They are more common in males, with a peak incidence between the ages of 30 and 50. In China, kidney stones are more prevalent in the southern regions compared to the northern regions, and their occurrence is notably higher in the summer compared to other seasons. Studies indicate that with the gradual warming of the global climate, the incidence of kidney stones in humans is also gradually increasing.

Metabolic Abnormalities

Most urinary tract stones are composed of metabolic byproducts in the body, and different types of stones can reflect corresponding metabolic abnormalities in the body. Common stone-forming components in urine include calcium, oxalate, uric acid, and cystine. Any physiological disturbance causing abnormal components may initiate stone formation and promote stone growth.

Local Factors

Stones caused by local factors in the urinary tract are often formed on the basis of other underlying conditions. Urinary tract obstruction, infection, and the presence of foreign bodies in the urinary tract are the main local factors that trigger stone formation. Obstruction can lead to infection and stone formation, and stones themselves act as foreign bodies in the urinary tract, exacerbating the degree of obstruction and infection.

Drug-Related Factors

Drug-induced kidney stones account for 1% to 2% of all stones and can be divided into two major categories:

Drugs with high urine concentration and low solubility, including acetazolamide, indinavir, silicates, and sulfonamide drugs, which are components of the stones themselves.

Drugs that can induce stone formation, including acetylazolamide, vitamins D and C, and corticosteroids, which in the process of metabolism lead to the formation of stones with other components.

Pain

Patients often experience pain in the lower back, and the severity of the pain depends on the size and location of the stone:

Large stones with limited mobility cause mild pain, presenting as dull or intermittent pain, and may even be painless.

Small stones with greater mobility within the kidney often cause severe renal colic.

Renal colic is a sudden and severe pain, often occurring from late night to early morning, starting from the lower back or flank and radiating down the ureter to the bladder and even the testicles. The pain can last from minutes to hours. During an episode, patients appear pale, restless, and may experience nausea and vomiting.

Hematuria

Hematuria mostly occurs after the onset of pain and is generally mild; in a minority of cases, it is gross hematuria, while in most cases, it is microscopic hematuria.

Stone Passage

A few patients may notice the spontaneous passage of small stones, commonly referred to as gravel in the urine, which is strong evidence for the diagnosis of urolithiasis.

Infection

A small number of stones may be complicated by urinary tract infection or may themselves be infected stones. In pediatric stone patients, secondary urinary tract infection may be the main clinical manifestation, but the presence of stones is easily overlooked at the time of diagnosis.

Immediate intervention is necessary when renal colic and infection occur. For infected patients, antibiotics should be promptly administered, and if necessary, renal puncture drainage may be performed. For patients with renal colic, mild pain can be managed with nonsteroidal anti-inflammatory drugs, combined with antispasmodic therapy. In cases of severe pain, pethidine may be administered for pain relief. Patients with bilateral ureteral stones and obstruction resulting in anuria should undergo immediate surgical treatment.

TCM treatment focuses on clearing heat and dampness, promoting urination, and removing stones, supplemented by regulating Qi and promoting blood circulation, and softening and dispersing concretions. Commonly used proprietary Chinese medicines include "Niaoduqing" and others, and commonly used prescriptions include "Bazheng San," "Sanjin Paitong Tang," and "Sini San."

Acupuncture therapy lacks evidence-based medicine support but may be used as an adjunctive therapy, including body acupuncture, electroacupuncture, and acupoint injection. Commonly used acupoints include Shenshu, Zhongwan, Jingmen, Sanyinjiao, and Zusanli. During an episode of renal colic, needling at the Sanyinjiao and Shenshu points, and/or the lumbosacral region on the back of the hand, can often provide rapid and effective analgesia.

The use of Chinese herbal medicine for stone clearance lacks large-scale clinical research to prove its safety, therefore, it should be conducted under the guidance of a TCM practitioner or herbalist.

Diet

For all types of kidney stone patients, it is important to increase fluid intake to facilitate the passage of small stones and reduce the formation of stones. Additionally, dietary adjustments should be made based on the composition of the stones.

Dietary Recommendations

The standard daily water intake should maintain a urine volume of 2000ml or more, with clear urine being ideal.

Dietary Restrictions

Patients with oxalate stones should avoid consuming concentrated tea, spinach, tomatoes, asparagus, and various nuts (such as peanuts).

Patients with uric acid and cystine stones should avoid foods high in purines (such as animal offal, pork, beef, lamb, shellfish, herring, sardines, and tuna), and also limit salt and protein intake while increasing the intake of fruits, vegetables, and whole grains.

Patients with absorptive hypercalciuria should avoid calcium-rich foods as much as possible, such as milk and soy products.

Lifestyle

Engage in moderate exercise daily, control body weight, and maintain regular sleep patterns.

There is no specific food or supplement that can effectively prevent kidney stones. It is important to maintain regular sleep patterns, engage in regular physical activity, cultivate good dietary habits, and adjust the dietary structure, such as maintaining a balanced diet and increasing the intake of fruits and vegetables, which are more valuable for the prevention of kidney stones.

For the general population, adjusting lifestyle, such as drinking adequate water and adjusting dietary structure, is important. Patients with hyperuricemia and primary hyperparathyroidism should actively treat the underlying diseases, which can help prevent and treat kidney stones.