There are mainly four types of kidney stones or calculi:
- Calcium stones: These are the most common (accounting for 60%-80% of all stones). The calcium that our body does not use goes to the kidneys, where it is retained and can combine with substances such as oxalate - present in many foods. Phosphate and carbonate are other substances with which calcium sometimes combines, and up to 40% of calcium stones are of mixed composition. It is therefore very important to consult your doctor to determine the origin, especially the characteristics of the nucleus that forms the kidney stone, in order to determine the most appropriate treatment.
- Struvite stones: Between 5% and 15% of stones are of this type. They are somewhat more frequent in women and are often the result of repeated or chronic infections in the urinary system. They can reach a large size and obstruct the kidney, ureters, or bladder.
- Uric acid stones: 5% to 10% of stones. More common in people who consume a lot of meat, seafood, and fish, and can also appear in cases where urine contains an excessive amount of this acid, such as in patients with gout, certain blood disorders, those undergoing chemotherapy, or those who have experienced rapid weight loss, among other cases.
- Cystine stones: 1% of kidney stones have this composition. They affect both sexes, although they are rare and are caused by a genetic disorder called cystinuria. This leads the kidneys to excrete too much cysteine, an amino acid present in muscles, nerves, and other parts of the body, into the urine.
According to the European Association of Urology (EAU), there is a 95% chance of passing a small stone within six weeks of experiencing renal colic. To this end, there are several types of treatment:
- Traditionally, it is recommended that for small or asymptomatic stones, six to eight glasses of water per day should be drunk to increase urine volume and help expel the stone. This is combined with dietary changes or food supplements that allow modification of the urine pH or prevent stone growth by reducing the possibility of crystal formation and aggregation.
- In some cases, the application of local heat is also recommended as a complementary treatment to relieve pain and nausea.
- In cases of severe pain, which is often frequent, anti-inflammatory drugs are necessary. In some cases, different analgesics or even hospitalization may be required. There are also other medications used for stone treatment, promoting their expulsion or dissolution.
- If symptoms persist, active treatment is needed to remove the stone from the urinary tract and allow adequate urine flow, as kidney stones can cause kidney infection and permanent organ damage or very serious complications. This type of treatment includes techniques that involve fragmenting the stone into very small pieces or directly capturing it whole through the ureter.
- For large and/or hard-to-reach stones not amenable to the above techniques, surgery is required.
Sources:
Spanish Association of Urology (AEU).
European Association of Urology (EAU) in collaboration with the EAU Urolithiasis Section (EULIS "Patient Information. Basic information on kidney and ureteral stones").
