Frequency and causes
Kidney stones affect 10–15% of people in the course of their lives. In Switzerland, up to 30,000 people per year develop this condition for the first time, with men more likely to suffer from kidney stones than women.
The formation of kidney stones is complex – in addition to genetic factors, which are not yet fully understood, environmental and nutritional influences in particular play a key role. Kidney stones usually occur when substances in the urine do not dissolve properly and therefore concentrate, crystallise and thus form stones. There are different types of kidney stones which vary in terms of composition. The most common type are stones made up of calcium salts (calcium oxalate and calcium phosphate), which account for over 80%, followed by uric acid stones and struvite stones.
Typical symptoms of kidney stones
The most dramatic manifestation of kidney stones is renal colic, which occurs when a kidney stone is unable to pass through the narrow ureter running from the kidney to the bladder. Renal colic pain is one of the most severe forms of pain a human being can experience, comparable only with the pain of childbirth. In addition to causing severe pain, the stuck kidney stone can block the flow of urine, which can in turn build up into the kidney and potentially damage it.
Diagnosing kidney stones
Depending on the type of stone in question, kidney stones can be diagnosed using a range of imaging methods. At the same time, various blood tests and urine analyses are performed to obtain further evidence to support the diagnosis. Since the type of kidney stone sheds light on what caused it to form and indicates what kind of treatment will be required, a stone analysis is carried out on all kidney stones wherever possible and the composition of the stone identified.
Painkillers are used to relieve acute renal colic, with the strength of the dose depending on the specific situation. In addition to this, the stones must be removed from the urinary tract.
In some cases, smaller stones may be excreted spontaneously via the urinary tract – with the help of medication. If this does not work, various technical, endoscopic or surgical methods can be used to break up the stones, with the fragments then being excreted in the urine or removed there and then as part of the operation.
Without adequate treatment, around 40–50% of all kidney stone patients suffer a relapse within five years. To prevent new kidney stones from forming, patients must pay attention to what they eat and drink, as this can affect the risk of developing kidney stones. As a general rule, patients are advised to avoid excessive consumption of meat (maximum of once a day), eat fruit and vegetables every day, and restrict their consumption of food and drink that is rich in oxalic acid (black/green tea, iced tea, spinach, rhubarb, peanuts, almonds, pistachios, wheat bran products, dark chocolate). They should not limit their calcium intake and drink plenty of fluids regularly to ensure that they pass at least two litres of urine per day. In addition to these dietary measures, certain medications, which counteract the mechanism behind the formation of urinary stones, can also be used to reduce the risk of kidney stones.