“A sharp pain in my side. Emergency room, CT scan, ultrasound, blood tests” and the diagnosis: “Probable kidney stone”. This is how Gianmarco ‘Gimbo’ Tamberi described, last night via Instagram, the unexpected event that forced him to postpone his departure for the 2024 Paris Olympics. “A violent pain in my side” is the alarm bell that announces renal colic, “the most typical symptom” of kidney stones, a common problem that can affect up to one in 10 people. But what is a kidney stone? What does it depend on? And how is it treated? The experts at the Niguarda hospital in Milan explain, in an in-depth article published on the website of the Asst Grande Ospedale Metropolitano.
“Kidney stones (or nephrolithiasis),” they describe, are created “when the concentration of lithogenic salts (calcium, uric acid, oxalate) in the urine increases, forming the first crystals which then, aggregating together, form the actual stone. This is a problem that affects 5 to 10% of the population, with a growing trend in recent decades, attributable to the greater consumption of animal proteins in our diet”. To avoid kidney stones, it is necessary to “keep the urine in a condition of undersaturation, that is, well diluted, ensuring constant and fractioned hydration to produce diuresis greater than 2 liters”. When they form, however, “stones are not all the same. There are different types: there are the most common ones formed by calcium salts, there are those of uric acid and those of struvite, resulting from a particular urinary infection. Then there can be those of cystine, caused by a rare hereditary pathology”, they specify from Niguarda. “To diagnose the type of calculus, it is essential to analyze the composition of the calculus once it has been expelled, through a chemical or crystallographic examination.”
But how does a kidney stone manifest itself? “The most typical symptom”, in fact, “is renal colic, that is, a violent pain in the side accompanied by vomiting and restlessness, due to the movement of the stone along the urinary tract. Sometimes there may only be a dull lumbago, like back pain. Another possibility is the occurrence of macro or microhematuria even without symptoms, that is, the presence of blood in the urine. In the case of ongoing renal colic”, it is recommended to “not underestimate the phenomenon that could recur over time. It is also recommended to carry out blood and urine tests to identify the so-called metabolic risk factors. It is also important to carry out radiological checks, such as an ultrasound of the urinary tract and/or a CT scan of the abdomen without contrast”.
It can be expelled but only if it is very small, even feeding helps
Therapy? Should kidney stones always be removed or can they go away on their own? “A stone of around 6 millimeters has a high chance of spontaneous expulsion – answer the specialists at Niguarda – while the percentage decreases as the size increases. When they reach larger dimensions, therapeutic intervention is necessary. Until a few years ago, the only hope was surgery, which through different techniques resolved the situation by removing or fragmenting the stones. Now, however, lithotripsy has become widespread, which allows treatment without cuts. The lithotripter is a machine capable of producing shock waves that are sent precisely, with the help of X-rays or ultrasound, so as to be concentrated on the stones themselves. These waves pass through the soft tissues of the body and discharge their energy on the stones so as to fragment them. Ultrasound is able to highlight the number and size of the stones, location and possible presence of dilation of the excretory ducts”.
Diet can also help. “The common therapy for all stones involves urinary dilution: drinking lots of liquids, lots of water, even tap water is fine – the experts clarify – There are studies that confirm this: having a daily hydration equal to or greater than 2 liters limits relapses, which are frequent for this type of pathology”. Another piece of advice is “significantly reduce the consumption of salt and animal proteins, such as meat, fish and eggs”.
“Contrary to what was thought until a few years ago – they finally point out from Niguarda – the diet must be normo-calcic. That is, foods such as milk, cheese and yogurt must not be banned”. Among other things, at times, “this could create major problems at a skeletal level, especially if the patient had high levels of calcium dispersion in the urine. In some cases, in fact, stones and osteoporosis can be correlated”.