Patient's question:
Lower ureteral stone, 66mmDoctor's answer:
Overview of Renal CalculiUrological stones are a common disease in urology and can be classified into renal calculi, ureteral calculi, bladder calculi, etc., depending on their location. Renal calculi are more common in middle-aged and young adults, with a higher prevalence in males than females. Renal calculi may exist for a long time without symptoms, especially larger ones. Smaller calculi have a larger range of movement. When small calculi enter the renal pelvis-ureteral junction or ureter, they cause severe peristalsis of the ureter to promote their excretion, leading to colicky pain and hematuria.
The pain caused by renal calculi can be dull or colicky. 40%–50% of patients have a history of intermittent recurrent pain. The pain is usually located in the waist and abdomen, often paroxysmal but can also be persistent. Some pain may only manifest as a dull ache or discomfort in the waist, and physical activity or exertion can trigger or worsen the pain. Colicky pain from renal calculi is severe, sharp, and often recurs suddenly, radiating to the lower abdomen, groin, or inner thigh. In females, it may radiate to the labia. During a recurrence of colic, patients may appear acutely ill, curling up in bed, pressing their hands tightly against the abdomen or waist, and even rolling in bed, groaning incessantly. Recurrences may last for hours or subside within minutes. Severe colic can cause pale skin, cold sweat, rapid and thready pulse, and even hypotension, leading to a state of collapse, accompanied by nausea, vomiting, abdominal distension, and constipation. During colic recurrences, urine output decreases, and polyuria may occur after the pain subsides. Hematuria is another major symptom of renal calculi. During pain episodes, gross or microscopic hematuria often occurs, with gross hematuria being less common. Physical activity can exacerbate hematuria. Renal calculi patients may excrete sand-like particles in their urine, especially during pain or hematuria recurrences, when urine contains sand grains or small calculi. When calculi pass through the urethra, they may cause obstruction or irritation.
Common complications of renal calculi are obstruction and infection, and many cases seek medical attention due to urinary tract infection symptoms. Obstruction can lead to hydronephrosis, causing a palpable mass in the upper abdomen or waist. The diagnosis of renal calculi is generally straightforward, based on medical history, physical examination, and necessary imaging tests such as X-rays and laboratory tests. Most cases can be confirmed through these methods. However, it is not sufficient to diagnose renal calculi alone; additional information about the size, number, shape, location, presence of obstruction or infection, renal function, composition, and potential underlying causes of the stones should also be considered. Without stone analysis or investigation into the etiology, recurrent stones that could have been prevented may lead to more adverse outcomes.
Ultrasound and plain X-ray radiography of the urinary system are the most commonly used diagnostic methods for renal calculi. Over 90% of renal calculi are visible on X-ray plain films, with visibility varying based on the chemical composition, size, and thickness of the stones. Stones with different compositions are ranked by their visibility as follows: calcium oxalate, calcium phosphate, magnesium phosphate, cystine, calcium-containing urates, and pure uric acid stones, which are not visible. Many factors can affect stone visibility on plain films, such as stone size, intestinal gas, and obesity, often leading to unsatisfactory results.
Ultrasound helps diagnose conditions like hydronephrosis and stones, particularly for asymptomatic stones and non-visualized uric acid stones. Ultrasound should be used in conjunction with other diagnostic methods. Renal calculi can be classified as calcium-based, uric acid, infectious, etc. Calcium-based stones are primarily composed of calcium oxalate and calcium phosphate, accounting for 80%–84% of all urinary stones. Other rare stones, such as those caused by long-term medication use, are more likely to form crystalline deposits, with sulfonamide drugs like sulfamethoxazole being particularly prone to crystallization. These can be prevented by taking alkalizing urine drugs or increasing fluid intake.
The goal of treating renal calculi is not only to alleviate pain and protect renal function but also to identify and address the underlying cause to prevent recurrence. Treatment should include general measures, etiological treatment, extracorporeal shock wave lithotripsy (ESWL), endoscopic stone removal, dissolution therapy, surgical treatment, traditional Chinese medicine, and dietary therapy. General measures include drinking plenty of water and acupuncture. Maintaining a daily urine output of 2000–3000 mL is ideal. Drinking large amounts of water with diuretics and antispasmodics can help small stones pass. To maintain nighttime urine output, drinking water before bed and after urination during the night is recommended. Diluted urine can slow stone growth and reduce postoperative recurrence. Increased urine output during infection can promote drainage and aid infection control. While excessive water intake may worsen colic, combining it with acupuncture and antispasmodics can help stones pass. If stones are small and the patient is healthy, physical activity and (Chinese and Western medications) may facilitate spontaneous stone passage.
In recent years, breakthroughs in renal calculus treatment have led to the widespread use of ESWL and endourological techniques, with surgery reserved for only a few cases.
Home Care for Renal Calculi Patients
The formation of renal calculi is often related to fluid intake. Water with excessive impurities or calcium salts should be purified and boiled before consumption. Magnetic water is preferable. Drinking boiled money grass tea can help with diuretic and stone-passing effects, as well as clearing heat, dampness, preventing urinary tract infections, and reducing colic recurrence. If magnetic water or money grass tea is inconvenient, drinking a moderate amount of tea water also has diuretic and stone-passing benefits. Individuals with a history of uric acid stones should limit intake of animal organs, goose meat, and sardines. While drinking plenty of water to prevent kidney disease, avoiding holding urine is crucial. Frequent urination helps expel bacteria, carcinogens, and stone-forming substances, reducing the risk of kidney and bladder damage.
For patients with existing renal calculi, medical experts agree that drinking plenty of water helps protect the kidneys and treat stones, but this should not be overemphasized. The specific approach depends on the patient's condition:
1. In hot weather, increased sweating can lead to concentrated urine, so drinking more water helps prevent stone formation and colic recurrence.
2. For smaller stones (including those with mild symptoms that patients may not yet recognize), encouraging increased fluid intake with medication can enhance urinary flushing, preventing sedimentation and promoting small stones to pass with urine. However, daily fluid intake should be around 2000 mL, divided into smaller amounts rather than consumed all at once.
3. If stones are larger than 1 cm, causing urinary tract obstruction, hydronephrosis, or accompanying conditions like hypertension, chronic kidney disease, severe ulcers, or heart disease, excessive water intake should be avoided to prevent worsening obstruction or triggering acute recurrences. Individuals genetically prone to ureteral stones should also develop a habit of drinking plenty of water and maintain a balanced diet, limiting high-oxalate foods like orange juice, cocoa, spinach, almonds, cashews, and raisins.
Renal calculus patients should also limit intake of foods that promote damp-heat, such as spinach, bayberry, tomato, cocoa, chocolate, pepper, potato, and chili, as well as high-calcium foods like milk, cheese, and high-phosphorus fatty meats and egg yolks. If tests reveal acidic stones, consuming more vegetables like greens and radishes can alkalinize urine. For alkaline stones, increasing meat intake can acidify urine. For oxalate-containing stones, walnuts are beneficial.
Renal calculus patients can have family members gently tap the renal area. Ureteral calculus patients should perform more jumping exercises to promote stone descent. Bladder calculus patients should strain during urination to facilitate stone passage.
How to Treat Renal Calculi?
Deng, a telecom employee in Fengxin County, Jiangxi Province, asked: "I have a stone in my right kidney and benign prostatic hyperplasia, with a digital rectal exam indicating a grade II prostatic hypertrophy. How should I treat the renal calculus? Is extracorporeal shock wave lithotripsy (ESWL) painful? Will it expel the stone? Is surgical treatment necessary for benign prostatic hyperplasia?"
Professor Liu Liu from the Urology Department of Beijing Jishuitan Hospital believes that renal calculi are a common urological condition, and treatment should consider:
1. Stone location.
2. Stone size.
3. Stone number.
4. Renal function.
Treatment options depend on these factors. If stones are not in the renal pelvis or calyces, no treatment may be needed. For stones smaller than 0.5 cm, conservative treatment may be effective. Stones between 0.5–1.5 cm may be treated with ESWL. Larger or multiple stones, or poor renal function, may require surgery. ESWL is a minimally invasive treatment that breaks stones, allowing them to pass through urine. It is generally well-tolerated but requires good renal function for effective stone clearance.
Benign prostatic hyperplasia is a common elderly male condition, often controlled with medication. Surgery is reserved for severe complications.
Can Beer Dissolve Renal Calculi?
Good news for beer lovers: Regular beer consumption reduces the risk of renal calculi. Researchers from the Helsinki Health Research Institute studied the diets of 27,000 Finns for three years and found that drinking one beer daily lowers the risk by 40%. The protective component in beer is unclear but may be ethanol, which enhances urine excretion, or (beer flower substances), which inhibits calcium excretion in urine. However, individuals with health issues or existing renal calculi should not avoid beer. Men should limit themselves to two cans daily, while women should stick to one can, but moderation is key. Excessive beer intake increases risks of obesity, cancer, and stroke.
Obesity and Renal Calculi
A new study shows that obese or overweight individuals are more likely to develop renal calculi than those with normal weight. However, for women with normal weight, the risk of painful stone precipitation is only half that of men. The study, published in the Journal of the American Medical Association, did not explain the gender disparity but noted that about 10% of U.S. men and 5% of women experience renal calculi in their lifetime, with annual treatment costs reaching $2 billion.
Researchers found that men with a body mass index exceeding 16 kg in early adulthood had a 40% higher risk, while women had a 70% higher risk. Additionally, women with the widest waists had a 70% higher risk than those with the narrowest, and men with the widest waists had a 48% higher risk.
Boston Brigham and Women's Hospital researchers suggest that fat tissue may impair insulin sensitivity, altering the uric acid environment conducive to stone growth. Further research is needed to confirm these findings and determine if weight loss reduces the risk of renal calculi.