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Kidney stone disease

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**Risk Factors and Dietary Influences:**
Dehydration, warm climates, obesity, and sedentary lifestyles increase risk.
– High dietary intake of certain foods and underlying metabolic conditions are risk factors.
– Calcium oxalate is a common component of kidney stones.
– Excess calcium intake may increase risk, while low dietary calcium intake is associated with a higher risk.
– High dietary sodium and fluoridated tap water may increase risk.
– Animal protein in Western diets can increase urinary excretion of calcium and uric acid.
– Excessive vitamin C and D intake may increase the risk of stone formation.

**Pathophysiology and Stone Formation:**
– Calcium oxalate crystals commonly form kidney stones.
– Supersaturation of urine leads to seed crystal formation.
– Factors like Randalls plaque and pathogenic bacteria can promote stone formation.
– Urease-positive bacteria like Proteus mirabilis promote struvite stone formation.
– Inhibitors like chelating agents and dietary magnesium/citrate can prevent stone formation.

**Diagnosis and Imaging Studies:**
– Kidney stone diagnosis is based on history, physical exam, and tests.
– Imaging studies like radiography and CT scans aid in detection and monitoring.
– Various diagnostic methods like CT scans, ultrasonography, and urine tests are used.
– Laboratory examinations include urine analysis, culture, blood tests, and 24-hour urine collection.
– Composition of kidney stones includes calcium oxalate, calcium phosphate, uric acid, struvite, and cystine stones.

**Types and Characteristics of Kidney Stones:**
– Calcium stones represent about 80% of cases in the US.
– Struvite stones form in the presence of urea-splitting bacteria.
– Different types of stones include calcium, infection, struvite, uric acid, cystine, and other rare types.
– Kidney stones can occur in the kidneys, bladder, or ureters based on their location.
– Stones under 5mm can pass spontaneously in 98% of cases.

**Prevention and Dietary Measures:**
– Preventative measures vary based on stone type.
Drinking fluids, thiazide diuretics, and citrate can help prevent calcium stones.
– Allopurinol is effective for high uric acid levels.
– Dietary modifications like fluid intake, limiting cola and animal protein, and increasing citrate intake can prevent stone formation.
– Magnesium intake, avoiding high vitamin C doses, and maintaining dilute urine are essential for prevention.

Kidney stone disease, also known as renal calculus disease, nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (renal calculus) develops in the urinary tract. Renal calculi typically form in the kidney and leave the body in the urine stream. A small calculus may pass without causing symptoms. If a stone grows to more than 5 millimeters (0.2 inches), it can cause blockage of the ureter, resulting in sharp and severe pain in the lower back or abdomen. A calculus may also result in blood in the urine, vomiting, or painful urination. About half of people who have had a renal calculus are likely to have another within ten years.

Kidney stone disease
Other namesUrolithiasis, kidney stone, renal calculus, nephrolith, kidney stone disease,
A color photograph of a kidney stone, 8 millimetres in length.
A kidney stone, 8 millimeters (0.3 in) in diameter
SpecialtyUrology, nephrology
SymptomsSevere pain in the lower back or abdomen, blood in the urine, vomiting, nausea
CausesGenetic and environmental factors
Diagnostic methodBased on symptoms, urine testing, medical imaging
Differential diagnosisAbdominal aortic aneurysm, diverticulitis, appendicitis, pyelonephritis
PreventionDrinking fluids such that more than two liters of urine are produced per day
TreatmentPain medication, extracorporeal shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy
Frequency22.1 million (2015)
Deaths16,100 (2015)

Most calculi form by a combination of genetics and environmental factors. Risk factors include high urine calcium levels, obesity, certain foods, some medications, calcium supplements, hyperparathyroidism, gout and not drinking enough fluids. Calculi form in the kidney when minerals in urine are at high concentration. The diagnosis is usually based on symptoms, urine testing, and medical imaging. Blood tests may also be useful. Calculi are typically classified by their location: nephrolithiasis (in the kidney), ureterolithiasis (in the ureter), cystolithiasis (in the bladder), or by what they are made of (calcium oxalate, uric acid, struvite, cystine).

In those who have had renal calculi, drinking fluids is a way to prevent them. Drinking fluids such that more than two liters of urine are produced per day is recommended. If fluid intake alone is not effective to prevent renal calculi, the medications thiazide diuretic, citrate, or allopurinol may be suggested. Soft drinks containing phosphoric acid (typically colas) should be avoided. When a calculus causes no symptoms, no treatment is needed. For those with symptoms, pain control is usually the first measure, using medications such as nonsteroidal anti-inflammatory drugs or opioids. Larger calculi may be helped to pass with the medication tamsulosin or may require procedures such as extracorporeal shock wave lithotripsy, ureteroscopy, or percutaneous nephrolithotomy.

Renal calculi have affected humans throughout history with a description of surgery to remove them dating from as early as 600 BC in ancient India by Sushruta. Between 1% and 15% of people globally are affected by renal calculi at some point in their lives. In 2015, 22.1 million cases occurred, resulting in about 16,100 deaths. They have become more common in the Western world since the 1970s. Generally, more men are affected than women. The prevalence and incidence of the disease rises worldwide and continues to be challenging for patients, physicians, and healthcare systems alike. In this context, epidemiological studies are striving to elucidate the worldwide changes in the patterns and the burden of the disease and identify modifiable risk factors that contribute to the development of renal calculi.

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