【Introduction】
When it comes to sudden and severe lower back pain, many people might think of lumbar muscle strain or problems with the spine. However, there is a disease whose pain intensity is comparable to that of childbirth, and it comes without any warning - it is kidney stones. As a global disease, kidney stones affect millions of people worldwide, not only causing great pain to the patients but also putting a heavy burden on the healthcare system, and the incidence rate is still on the rise.


【Understanding Kidney Stones】
Kidney stones are not an isolated disease; they are closely related to a variety of systemic diseases, especially cardiovascular diseases, diabetes, metabolic syndrome, and obesity. These diseases can all increase the risk of developing kidney stones.

To understand kidney stones, one must first understand the basic functions of the kidney system - the urinary system consists of the kidneys, ureters, bladder and urethra. The kidneys act like "human filters", filtering blood to produce urine. The urine flows through the ureters into the bladder for storage, and is eventually expelled from the body through the urethra. During the formation of urine, the kidneys remove metabolic waste and excess substances, reabsorb necessary solutes, and regulate water reabsorption to maintain the balance of water and electrolytes in the body.

Kidney stones are solid masses formed when certain substances in urine (such as oxalic acid, calcium, uric acid, etc.) accumulate to an excessive level, exceeding the solubility capacity of urine, and gradually crystallize and aggregate. Once formed, these stones may not cause obvious symptoms when they are small in size. However, if their size increases or they detach and enter the ureter, they will block the urinary tract, thereby causing severe pain, hematuria and other discomforts, and even damaging the kidney function. It is worth noting that the ureter has three natural anatomical narrow areas - the ureter-kidney pelvis junction (UPJ), the renal pelvis margin, and the ureter-bladder junction (UVJ), which are the places where stones are most likely to get stuck when they detach, and are also the main causes of severe pain.


【Diagnosis and Treatment】
Although the typical symptoms of kidney stones are recognizable, diagnosis still requires imaging examinations. The preferred method is non-contrast imaging (such as urinary tract CT), which can not only clearly determine the size, shape, and location of the stones, but also avoid the potential risks associated with contrast agents, and can also assess whether there is hydronephrosis or damage in the kidneys. After diagnosis, the treatment plan will be tailored according to the specific condition of the patient. The core principle is to relieve symptoms, expel the stones, protect renal function, and prevent complications.

Basic Treatment
For patients with smaller stones (diameter < 5mm), without obvious obstruction and mild symptoms, the preferred treatment is basic therapy, which includes: appropriate analgesic treatment (to relieve severe colic), antiemetic treatment (to improve gastrointestinal reactions), adequate water intake (daily water intake of 2000-3000ml, to promote the expulsion of small stones), and when necessary, the use of antibiotics (to prevent or treat urinary tract infections). At the same time, drug lithotripsy therapy (such as α-receptor blockers) can be combined to help relax the smooth muscle of the ureter and facilitate the spontaneous expulsion of the stones.

Surgical Intervention
Whether the calculi can be expelled on their own mainly depends on the size, shape, location of the calculi, as well as the patient's ureteral anatomy:

Most kidney stones with a diameter of less than 5 millimeters can be naturally expelled through basic treatment and with the aid of medication;
For stones with a diameter of more than 7 millimeters, or those that have not moved within 4 to 6 weeks, have caused urinary tract obstruction, or have led to kidney hydronephrosis, surgical intervention is usually required.

The two most commonly used surgical methods in clinical practice at present are:
Ureteroscopy + Laser Lithotripsy: Through the endoscope, enter the ureter and locate the stone. Then, use the laser to break it into small pieces, and use the stone removal basket to extract the fragments. This method has minimal trauma and quick recovery, and is suitable for stones in the middle and lower segments of the ureter that are incarcerated.
Extracorporeal Shock Wave Lithotripsy: Utilize external shock waves to break kidney stones into tiny fragments, allowing the patient to excrete them through urine. No surgery is required. It is suitable for kidney stones with a diameter of less than 2 cm and a relatively shallow location.


【Market Demand and Value Prospects】
The medical training market is expanding.
The diagnosis and treatment of kidney stones require high operational precision. Especially for minimally invasive lithotripsy and endoscopic operations, the learning curve for novice physicians is long, and there is an urgent need for clinical training. Appropriate simulation training models (such as kidney stone lithotripsy training models, ureteroscopy operation models), as well as VR simulators and other training equipment, can help physicians improve their skills in a risk-free environment, fill the gap in clinical training, and align with the global policy orientation for standardized physician training.

There is a high demand for pre-visit and follow-up services.
The recurrence rate of kidney stones is extremely high. The 5-year recurrence rate is approximately 30%, and the 10-year recurrence rate is about 50%. Moreover, high-risk groups (such as those with recurrent stones, renal failure, solitary kidney, and childhood stones) need regular screening. This directly leads to the emergence of related demands. These include 24-hour urine collection tests, analysis of stone composition (such as infrared spectroscopy detection), preventive products (such as dietary products that control oxalate and calcium), and simple detection tools required for long-term follow-up. The demand group is stable and has sustainability.

The market size continues to expand.
The global market for kidney stone management (including diagnosis, treatment, and prevention) is valued at approximately 2.6 billion US dollars in 2025. It is projected to grow at a compound annual growth rate of 5.1% to 4.1 billion US dollars by 2035, showing a strong growth momentum. Among them, products related to the diagnosis, treatment, and prevention of calcium oxalate stones (accounting for 75-80% of all cases), as well as equipment related to extracorporeal shock wave lithotripsy (ESWL), occupy the majority of the market share and have become the core growth drivers.


【Summary】
The sudden and severe pain caused by kidney stones is an urgent warning signal from the body. It not only relates to the health of the urinary system, but may also be associated with various diseases throughout the body. Understanding its typical symptoms can help us quickly identify and seek medical treatment in time; mastering the diagnosis, treatment and prevention knowledge can help us better deal with the disease and reduce the risk of recurrence.

With the continuous advancement of medical technology and the rise of the medical 3D printing industry, it is bringing revolutionary breakthroughs to the diagnosis, treatment, training and prevention of kidney stones, becoming an important support for maintaining the health of the urinary system, and also demonstrating its broad market value and industry potential.