What is a Kidney Stone?

A kidney stone refers to a various amount of different crystallizations due to oversaturations of chemicals in the kidney. Due to the most common variation, calcium oxalate (70-80%) [1], having a crystal structure with a surface resembling serrated spikes, it is extremely painful to pass through the ureter (tract between bladder and kidney) and later the urethra (urinary tract), since the kidney stones often are larger than the tract, so they brush against the side [2].

The inadequate treatment of kidney stones does not contribute to a less painful experience for the patients. Small stones comprising roughly 80 to 90 percent of the cases are treated with painkillers and water, while the stones naturally move through the excretory system. For larger stones(especially >10 mm) [2] this simply is not an option where approximately 10 to 20 percent of all kidney stones require surgical removal [3]. Here the stones may be treated with Shock wave lithotripsy, which is the medical term for the noninvasive procedure in which the kidney stones are broken up via pressure to then be naturally peed out. If the stones are very large and/or irregular, different types of surgery may come into play as treatment. To sum up the treatment the options are painkillers and water, shockwaves and then painkillers and waters or actual surgery.

Furthermore once a patient has had one kidney stone, the estimated risk of it ever occurring again is as high as 80% [4] if no preventative actions are taken. Only the subsequent 3-5 years show an increase to an estimated risk of 30%-50% [5] according to various studies.

Diagnosis of Kidney Stones

A patient may experience one or perhaps multiple of the following symptoms of kidney stones and seek a doctor:

• fever and chills
• nausea and/or vomiting
• vague pain or stomach ache that don't seem to disappear
• abnormal urine, that smells bad, looks cloudy and/or contains blood

When a doctor finds that a patient is suffering from kidney stones, the doctor will usually do imaging tests to figure out the position, shape and size of the kidney stone. There are different imaging tests that can be done, for example a high resolution CT. Based on imaging tests the doctor will decide a suitable treatment.

After the kidney stone/s passes or are removed through other procedures. The kidney stones composition will be determined. meaning that the type of kidney stone (calcium oxalate, struvite, cysteine or uric acid) will first be known then. finding the type of kidney stone can help doctors determine how to best prevent the patient getting another kidney stone [6]. For example, diets low in calcium and oxalate may be suggested to patients with calcium oxalate stones but not work if you have a uric acid stone.

Causes of Kidney Stones

Often there is not one single cause to a kidney stone but multiple factors that increase the risk. One of the most well known reasons for it is lack of hydration. When there are more crystal-forming substances (Calcium, Oxalate and uric acid) than the fluid in one's urine can dilute; the substances can form into kidney stones. Another reason could be that one’s urine could lack substances that prevent the crystals from sticking together. The most common type of kidney stone is the calcium stones, that is usually in the form of calcium oxalate [7]. Oxalate can be found in certain fruits, vegetables, nuts and chocolate, and that is why one’s diet also can heavily affect the formation of kidney stones [8].

Where To Find Kidney Stones?

People suffering from kidney stones can be found all across the globe, and so it is a global problem. though some regions have much higher prevalence of kidney stones than others. For example, a study in southern Iran found that out of the over 10000 people examined for history of kidney stones 21.11% had a history of kidney stones [9], whereas for example Denmark has a 5-10% prevalence of kidney stones [10]. when comparing the rate of kidney stones in countries with temperate climates to those of countries with arid climates, such as Iran and Denmark. Countries with more arid climates tend to have a higher prevalence of kidney stones. It is speculated that this is because the hot temperatures concentrate the stone forming materials in the urine [11].

References

1. Bershow, S. (2023, October 3). Preventing kidney stones before they form. Mayo Clinic Health System. https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/preventing-kidney-stones
2. National Center for Biotechnology Information. (2015). Kidney stones: Treatment and prevention of recurrence. In Kidney Stones: Medical management guidelines. https://www.ncbi.nlm.nih.gov/books/NBK348937/
3. West Tennessee Healthcare. (2020, October 30). What to expect when you need surgery for kidney stones. https://www.wth.org/blog/what-to-expect-when-you-need-surgery-for-kidney-stones/
4. Mayo Clinic Staff. (2021, February 9). Mayo Clinic Q&A: Preventing kidney stones. Mayo Clinic News Network. https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-q-and-a-preventing-kidney-stones/
5. Urology Times. (2022, October 26). Managing stone recurrence: What practitioners should know. https://www.urologytimes.com/view/managing-stone-recurrence-what-practitioners-should-know
6. National Kidney Foundation. (n.d.). Kidney stones. https://www.kidney.org/kidney-topics/kidney-stones
7. Ferraro, P. M., Taylor, E. N., Gambaro, G., & Curhan, G. C. (2021). Dietary intake and risk of incident kidney stones: Results from three prospective cohort studies. PubMed Central. https://pubmed.ncbi.nlm.nih.gov/34132361/
8. WebMD. (n.d.). Kidney stones: Causes and risk factors. https://www.webmd.com/kidney-stones/kidney-stones-food-causes
9. Yang, L., Zheng, X., Han, P., et al. (2022). A review of advances in the research of kidney stones. BMC Urology, 22, 32. https://bmcurol.biomedcentral.com/articles/10.1186/s12894-022-01161-x
10. Pro.medicin.dk. (2023). Nyresten. https://pro.medicin.dk/sygdomme/sygdom/318343
11. Aggarwal, K. P., Narula, S., Kakkar, M., & Tandon, C. (2021). Kidney stones: Causes, symptoms, and treatment. Scientific Reports, 11, 4251. https://www.nature.com/articles/s41598-021-04251-2
12. Fisang, C., Anding, R., Müller, S. C., Latz, S., & Laube, N. (2015). Urolithiasis: An interdisciplinary challenge. PubMed Central. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6390834/
13. Trinchieri, A. (2016). Epidemiology of urolithiasis: An update with emphasis on Europe. Journal of Nephrology, 29, 349-355. https://link.springer.com/article/10.1007/s40620-016-0283-8
14. Zisman, A. L. (2017). Effectiveness of treatment strategies for kidney stones. PubMed Central. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5817324/
15. University of Florida Health. (n.d.). Stone disease. UF Urology. https://urology.ufl.edu/patient-care/stone-disease/
16. Mayo Clinic Staff. (2023, October 3). Kidney stones: Symptoms & causes. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/kidney-stones/symptoms-causes/syc-20355755
17. Mayo Clinic. (n.d.). Predicting symptomatic recurrence of kidney stones. https://www.mayo.edu/research/documents/predicting-symptomatic-recurrence-of-kidney-stones/doc-20156688