How Do You Get Kidney Stones?

Kidney stones develop when urine contains a high concentration of certain minerals or waste products, allowing crystals to form and sometimes grow into stones. Low fluid intake is a common contributor, but diet, family history, medicines, and medical conditions can also affect a person’s risk.

How kidney stones form

How do you get kidney stones? Kidney stones form when urine becomes concentrated enough for minerals, salts, or other substances to come out of solution and create tiny crystals. These crystals may pass unnoticed, but they can also join together and enlarge into a stone within the kidney.

Urine normally contains substances that help keep crystals dissolved or prevent them from sticking together. When there is too little urine volume, or when levels of certain substances are high, that balance can change. A stone may remain in the kidney or move into the ureter, the narrow tube that carries urine from the kidney to the bladder.

Having a kidney stone does not necessarily mean a person has done anything wrong. Stones usually result from a combination of hydration habits, diet, body chemistry, inherited tendencies, medications, and certain health conditions. The underlying reason can differ considerably from one person to another.

The main reasons urine forms crystals

Not drinking enough fluids is a frequent reason stones develop. With less water available to dilute urine, crystal-forming substances become more concentrated. Fluid needs vary with climate, physical activity, work conditions, illness, pregnancy, and individual health, so there is no single amount that suits every person.

High losses of fluid through sweating, vomiting, diarrhea, fever, or intense exercise can also make urine more concentrated. Some people may notice that they are more likely to develop stones during hot weather or when they have limited access to water.

Food choices can contribute for some people, particularly when they repeatedly increase substances involved in their particular stone type. Examples include a very high salt intake, large amounts of animal protein, or frequent intake of foods rich in oxalate in someone prone to calcium oxalate stones. However, overly restrictive diets are not appropriate for everyone, and prevention should be tailored to the stone composition and a clinician’s advice.

Calcium in food is often misunderstood. For most people, normal dietary calcium is important for bone health and may help bind oxalate in the digestive tract. Cutting out calcium-rich foods without medical guidance is not usually the best way to prevent calcium-containing kidney stones.

Types of kidney stones and why type matters

Several types of kidney stones can develop. Calcium stones, most often calcium oxalate and sometimes calcium phosphate, are the most common. They can be associated with concentrated urine, high urine calcium or oxalate, high sodium intake, low citrate levels, and other metabolic factors.

Uric acid stones may form when urine is persistently acidic and can be more likely in people with gout, metabolic conditions, dehydration, or diets high in purines from some animal foods. Struvite stones are linked to certain urinary tract infections and can grow more quickly. Cystine stones are rare and result from an inherited condition called cystinuria, which causes excess cystine in the urine.

Knowing the stone type is useful because prevention is not identical for every stone. If a person passes a stone, a clinician may recommend saving it for laboratory analysis. In people with recurrent stones or a high risk of recurrence, urine and blood testing may identify treatable contributors.

Kidney stones are part of a broader range of kidney stone conditions that may require individualized assessment, especially when stones recur, cause blockage, or occur alongside infection.

Who is more likely to develop kidney stones?

A previous kidney stone is an important risk factor for another one. A family history may also raise risk because inherited traits can influence how the body handles calcium, oxalate, uric acid, citrate, and other substances in urine.

Medical conditions associated with stone formation include recurrent urinary tract infections, gout, chronic diarrhea, inflammatory bowel disease, and conditions that affect absorption in the digestive system. Some people develop stones after intestinal surgery or weight-loss surgery because changes in absorption can increase urine oxalate or reduce urine volume.

Excess body weight, insulin resistance, and diabetes may be associated with changes in urine chemistry that favor certain stones, particularly uric acid stones. Reduced mobility, some kidney or parathyroid disorders, and anatomical differences in the urinary tract can also contribute.

Certain medicines and supplements can increase stone risk in particular circumstances. This does not mean prescribed treatment should be stopped. Anyone concerned about a medicine, vitamin, or supplement should discuss it with the prescribing clinician, who can consider alternatives or monitoring when appropriate.

• Personal or family history of stones
• Low fluid intake or repeated dehydration
• High sodium intake or an unbalanced restrictive diet
• Recurrent urinary infections or urinary tract blockage
• Digestive diseases or surgery affecting nutrient absorption
• Specific inherited, metabolic, or endocrine conditions

Symptoms and how kidney stones are diagnosed

Small stones may cause no symptoms and may leave the body in urine without being noticed. A stone that moves into the ureter can cause sudden, intense pain in the side, back, lower abdomen, or groin. The pain may come in waves as the ureter contracts around the stone.

Other possible symptoms include blood in the urine, nausea, vomiting, a frequent urge to urinate, pain during urination, or cloudy or unusually smelling urine. Symptoms alone cannot confirm a kidney stone, because urinary infections and other abdominal or pelvic conditions can cause similar problems.

A clinician may use a medical history, examination, urine testing, blood tests, and imaging to determine whether a stone is present and whether there is obstruction or infection. Ultrasound is often used, while computed tomography may be considered when more detailed imaging is needed. The evaluation also helps identify situations in which prompt treatment is important.

For people with repeated stones, assessment may include a 24-hour urine collection and analysis of a recovered stone. These tests can help clinicians recommend targeted steps rather than relying on general dietary restrictions alone.

Treatment and passing a stone

Treatment depends on the stone’s size, location, composition, symptoms, and whether it is blocking urine flow or associated with infection. Many small stones can pass naturally with time, fluids as advised by a clinician, and medication to manage pain or nausea. A doctor may sometimes prescribe medicine to help relax the ureter and support stone passage.

Larger stones, persistent pain, blockage, impaired kidney function, or infection may require a procedure. Options can include shock wave treatment to break stones into smaller pieces, ureteroscopy to remove or fragment a stone through the urinary tract, or a procedure through a small incision for selected large or complex stones.

Procedural choices should be made with a urologist after imaging and clinical evaluation. Kidney stone treatment may involve watchful waiting, medication, or minimally invasive procedures depending on the individual situation.

Acıbadem Health Point’s multidisciplinary specialists and JCI-accredited hospitals diagnose and treat kidney stone conditions for international patients, with care plans based on the stone and the person’s overall health needs.

Practical ways to help prevent future stones

For many people, increasing fluid intake enough to produce pale, regularly passed urine is a central preventive measure. Water is generally a suitable choice. A clinician can give individualized fluid advice for people with heart failure, advanced kidney disease, or another condition that requires fluid restriction.

Reducing excess salt may help lower calcium in urine and also supports cardiovascular health. Eating a balanced diet with vegetables, fruits, and appropriate calcium-containing foods can be helpful. People prone to calcium oxalate stones may be advised to moderate, rather than automatically eliminate, high-oxalate foods and to eat them with calcium-containing foods when appropriate.

Moderating very high amounts of animal protein may be recommended for certain stone types. Maintaining a weight that supports overall health and treating recurrent urinary tract infections promptly can also be important. Alcohol, herbal products, and supplements should be discussed with a clinician if a person has recurrent stones or other medical conditions.

Prevention works best when it is personalized. A urologist, nephrologist, or dietitian may recommend specific dietary adjustments or medicines when urine testing shows a particular abnormality. These measures can reduce risk but cannot guarantee that another stone will never form.

When to seek medical care

Medical assessment is advisable for new severe flank or abdominal pain, visible blood in the urine, persistent urinary symptoms, or suspected kidney stone symptoms. A clinician can check for blockage, infection, and other conditions that may need different treatment.

Urgent medical care is needed if pain is accompanied by fever, chills, confusion, repeated vomiting, inability to keep fluids down, very little or no urine, or difficulty urinating. These symptoms can indicate infection or obstruction and should not be managed at home.

People who are pregnant, have one kidney, known kidney disease, a weakened immune system, or recurrent stones should seek medical advice promptly if symptoms occur. Follow-up is also worthwhile after a first stone, especially if the stone is not captured for analysis or symptoms return.

Frequently asked questions