Kidney Stones (Nephrolithiasis)

Nephrolithiasis – colloquially called kidney stones – (synonyms: Fixed renal stone; calixurolithiasis; calcium nephrolithiasis; caliceal stone; caliceal stones; congenital nephrolithiasis; calculus in the renal caliceal system; coral stone; nephrolith; nephrolithiasis; nephrolithiasis of the renal pelvis; renal abscess with stone; Renal effusion stone; Renal pelvic effusion stone; Renal pelvic diverticulum with stone; Renal pelvic diverticulitis with stone; Renal pelvic diverticulosis with stone; Renal pelvic calculus; Renal pelvic calculus; Renal pelvic solitary stone; Renal pelvic stones; Renal calcium oxalate stone; Renal caliceal calculus; Renal caliceal calculus; Renal colic due to stone; Renal calculus; Renal calculi; Renal upper caliceal calculus; Renal parenchymal stone; Renal stone of the upper caliceal group; Renal stone discharge; Renal stones; Renal stone grit; Renal stone colic; Renal stone disease; Renal lower caliceal calculus; Renal lower caliceal stone; Oxalate nephrolithiasis; Pelviolithiasis [renal pelvic stone]; Recurrent nephrolithiasis; Recurrent renal stone; Urate deposition in kidney; Urate stone in renal pelvis; Encapsulated renal pelvic stone; ICD-10-GM N20. 0: renal stone) refers to the formation of urinary stones in the kidney. Nephrolithiasis is a form of urolithiasis (urinary stones in the urinary tract – renal pelvis, ureters (ureters), urinary bladder, urethra (urethra)). Urinary stones are caused by an imbalance in the physicochemical composition of urine with formation of salt crystals. Nephrolithiasis can be classified based on the cause of formation:

Cause of origin Stone type Frequency in %
Acquired metabolic disorder Calcium oxalate stone 75
Uric acid stone 11
Uric acid dihydrate stone 11
Brushite stone 1
Carbonate apatite stone 4
Urinary tract infection Struvite stone 6
Carbonate apatite stone 3
Ammonium hydrogen urate stone 1
Congenital metabolic disorder Cystine stone 2
Dihydroxyadenine stone 0,1
Xanthine stone very rare

Sex ratio: men are more frequently affected than women; contrary to previous evidence, there are several studies that the distribution between the sexes is equalizing over the last decades or increasing at the expense of women. Peak incidence: The peak incidence of nephrolithiasis is between the ages of 30 and 60 years. The prevalence (disease incidence) is 5% in Germany, 5-9% in Europe and 12-15% in the USA. The incidence has increased significantly in Western industrialized countries. Kidney stones occur particularly often in dry and hot regions (10-15 %). Course and prognosis: Nephrolithiasis may be asymptomatic and therefore often remains undetected. The size of the stones can vary from a few millimeters to several centimeters. Up to a diameter of 2 mm, the stones pass spontaneously (by themselves) through the urine in the majority of cases. Stones larger than 5-6 mm in diameter rarely pass spontaneously. When the stone passes, this is mainly associated with colicky pain and a strong urge to urinate. In the majority of cases, kidney stones occur on one side. In 50% of patients, nephrolithiasis (kidney stones) occurs recurrently. In 10-20% of patients, at least 3 recurrent episodes must be expected. By so-called metaphylaxis (urinary stone prophylaxis), which depends on the type of stone and the cause, the recurrence rate can be reduced below 5 %. Basic rules include drinking plenty of fluids (> 2.5 l/day), low animal proteins (protein), low-salt and high-potassium diet, weight normalization and physical activity. Comorbidities (concomitant diseases): Urolithiasis is associated with an increased risk of myocardial infarction (heart attack) (31%). Furthermore, there is an increased risk of urothelial carcinoma (malignant tumors of the transitional tissue (urothelium) lining the urinary tract).