Why Do Kidney Stones Form? Causes & Risk Factors

Last updated: May 18, 2026

Kidney stone issue is a very common problem at my urology office. After reviewing the literatures on the incidence of kidney stone, there was a proportion for at least 10% of US and European population that facing this problem one time in their whole lifetime. But when I try to get more research here, I was surprisingly with the numbers that coincidently flew up to touch a 17% of kidney stone rate showed. In this topic we will figure out about why kidney stone happens.

Why this happen? – This question is extremely hard to give a certain answer, because it happens from multifactorial factors. When we all know that kidneys are the organ which functioning on infiltration waste-products from our body and then excrete out by urination, so the kidney is the place where some ions for example Calcium, Phosphate, Uric acids and Oxalate – always be in a high concentration. When ions reached their maximum concentration, then they start stone formation.

High ions concentration inside the kidney makes kidney stone

Kidney stone is caused from 2 major factors.

Host factor
- Race – African American and Caucasian were reporting more incidence than Asian, also some specific race especially Cambodian and Northern east part of Thai population usually suffered a genetic-related disease.
- Sex – Men are suffering more than women with a ratio around 2:1 worldwide.
- Age – Aging is reported around between 40 – 60 years old.
- Underlying medical history – Obesity and Diabetes can increase the rate 55% and 59%, obviously. Basically, for all those diseases will make our body excrete more ions in the urine.

Human race is one of important factor on kidney stone incidence

Male suffers with kidney stone more than female

Medical history for example – Diabetes rises the kidney stone rate

Environmental factors
- Geographic location – The countries area which located in tropical climate has more reported on the incidence. The reason is, people who live in hot weather condition tend to lose body fluid easily from sweating and consequently will experienced in less urine output that will make urine ions more concentrated.
- Water intake – Plenty of water intake is the easiest way to reduce the risk. In every 500 mL of increasing daily water intake will significantly reduce the incidence. (Recommendation daily water intake – 2,500 mL)
- Nutrition – High sodium intake, high oxalate intake, high Vitamin C intake, imbalance calcium intake are all involved problems and it tend to increase more risk of stone formation.
- Less citrate intake – Citrate ion possessing an effective on anti-stone, it is riches in Citrus fruit for example lemons. A cup of lemonade juice daily is recommended in patients who aware on stone formation.

Geographic location also play role in kidney stone incidence

Plenty of water intake is the easiest way to reduce kidney stone rate

Citrate is rich in Lemon and Citrus fruit

Sometimes kidney stone has another name called a metabolic disease because lots of involvement caused that. It might make the patients suffering from this kind of problem. Well educated patient with a strong Doctor-Patient binding would require for the possibly chronic problem like this – Kidney stone problem.

Any questions, you can feel free to discuss with me.

If you have recurrent kidney stones or would like a tailored prevention plan, Dr. Soarawee Weerasopone offers specialist consultations at Bangkok Hospital Headquarters. Book a Consultation.

Frequently Asked Questions about Kidney Stone Formation

Why do kidney stones form?

Kidney stones form when certain minerals and ions in the urine, such as calcium, oxalate, phosphate, and uric acid, reach a concentration high enough to crystallize. The kidneys normally filter these substances from the blood, but when fluid intake is low or dietary intake is excessive, these ions accumulate and begin to aggregate into stones.

Who is most at risk of developing kidney stones?

Kidney stones are more common in men than women at a ratio of approximately 2:1, and most commonly occur between the ages of 40 and 60. People with obesity, diabetes, or a family history of kidney stones face significantly higher risk. Those living in tropical climates are also more susceptible due to increased fluid loss through sweating.

Can drinking more water prevent kidney stones?

Yes. Increasing fluid intake is one of the most effective and practical ways to reduce kidney stone risk. Every additional 500 mL of water per day significantly lowers the risk by diluting urinary ion concentrations. A daily water intake of at least 2,500 mL is recommended for stone prevention.

What foods increase the risk of kidney stones?

A high intake of sodium, oxalate-rich foods (such as spinach and nuts), excess vitamin C supplements, and imbalanced calcium intake can all increase the risk of stone formation. High-protein diets and excessive animal meat consumption raise urinary uric acid levels, contributing to uric acid stones.

Does lemon juice really help prevent kidney stones?

Yes. Lemon and other citrus fruits are rich in citrate, a natural inhibitor of kidney stone formation. Citrate works by binding to calcium in the urine, preventing crystal aggregation. Drinking a glass of lemon juice daily is a simple and evidence-supported dietary measure for patients at risk of calcium oxalate stones.

Disclaimer: This content is written and reviewed by Dr. Soarawee Weerasopone, a board-certified urologist at Bangkok Hospital Headquarters. It is intended for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any medical treatment.

Medically written & reviewed by: Dr. Soarawee Weerasopone (Dr. Pom) — Board-Certified Urologist, Bangkok Hospital Headquarters. International Fellow: Baylor College of Medicine (USA) · Juntendo University (Japan) · Chang Gung Memorial Hospital (Taiwan).

Dr. Soarawee Weerasopone

Dr. Soarawee Weerasopone (Dr. Pom) is a board-certified urologist at Bangkok Hospital Headquarters, specializing in Men’s Health, Robotic Surgery (Da Vinci System), and Kidney Stone treatment. He has completed international fellowships at Baylor College of Medicine (USA), Juntendo University Hospital (Japan), and Chang Gung Memorial Hospital (Taiwan). All medical content on this site is written and reviewed by Dr. Soarawee based on his clinical experience and international training.