Kidney stones are one of the most common urological problems nephrology patients ask about. Knowing what causes them, how to recognize the pain, how they are diagnosed and treated, and what actually helps prevent them can make the condition far less overwhelming to manage.
Key Takeaways
- Kidney stones form when minerals and salts crystallize in the urine instead of staying dissolved.
- Pain is usually sharp and radiates from the flank to the back, often with blood in the urine.
- Diet, dehydration, family history, and certain medical conditions all raise the risk.
- Treatment ranges from watching and waiting to shock wave therapy or surgical removal, depending on stone size.
- Hydration and diet changes are the most effective ways to prevent stones from recurring.
What Are Kidney Stones?
Kidney stones are hard deposits that form inside the kidneys when minerals and salts in the urine crystallize together instead of staying dissolved. A stone can be as small as a grain of sand or grow large enough to fill part of the kidney’s inner structure. Most start small and cause no symptoms until they begin to move toward the ureter, the tube that carries urine to the bladder.
What Are the Different Types of Kidney Stones?
Not all kidney stones are the same, and the type often determines both the cause and the treatment approach. The most common types include:
- Calcium oxalate stones, the most frequent type, linked to diet and fluid intake
- Calcium phosphate stones, sometimes associated with certain metabolic or hormonal conditions
- Uric acid stones, more common in people with gout, high-protein diets, or chronic dehydration
- Struvite stones, which can form after certain urinary tract infections and tend to grow quickly
- Cystine stones, a rarer type linked to a hereditary condition that causes the kidneys to excrete too much of a specific amino acid
A nephrologist can determine the stone type through lab testing, which helps guide long-term prevention strategy rather than just treating the current stone.
Common Symptoms of Kidney Stones
Recognizing Kidney Stone Pain
Kidney stone pain has a fairly distinct pattern, a sharp, radiating pain in the flank that can spasm down the back. Blood in the urine and unusual sensitivity during ordinary movement are also common. Because of this, kidney stone pain is sometimes mistaken for back spasms, appendicitis, or gallbladder problems.
Early Warning Signs
Early warning signs are worth paying attention to before pain becomes severe. These include brief twinges of pain, visible blood in the urine, and small grains passing in the urine. Nausea, a persistent urge to urinate, and cloudy or foul-smelling urine can also appear as a stone moves. Catching these early can help prevent more serious complications down the line.
What Causes Kidney Stones?
Diet plays a major role in whether kidney stones form. Diets high in protein, calcium, and sodium are the most common contributors. Nephrologists typically recommend keeping sodium under 2 grams a day and protein to a moderate 40 to 60 grams a day for patients prone to stones, along with drinking more water to help flush the kidneys.
Less commonly, stones form from uric acid buildup, often tied to diets heavy in alcohol and seafood. That same dietary pattern also raises the risk of gout, so it is worth addressing both at once.
Beyond diet, several other factors raise the risk of forming stones. Chronic dehydration concentrates the urine and makes crystals more likely to form. A family history of kidney stones increases individual risk considerably, and certain conditions, including obesity, inflammatory bowel disease, hyperparathyroidism, and recurring urinary tract infections, can all make stone formation more likely. Some medications, such as certain diuretics and calcium-based supplements, can also contribute in susceptible patients.
How Kidney Stones Are Diagnosed
A suspected kidney stone is usually confirmed through a combination of imaging and lab work. A CT scan is the most sensitive way to detect stones and pinpoint their size and location, though ultrasound is sometimes used first, particularly when limiting radiation exposure matters. A urinalysis can detect blood or crystals in the urine, and blood tests may be used to check kidney function and rule out related metabolic issues.
If a stone passes on its own, a doctor may ask the patient to strain their urine to catch it for lab analysis. Knowing the stone’s composition helps target prevention efforts far more precisely than general advice alone.
What Are the Treatment Options for Kidney Stones?
Treatment depends heavily on the size, location, and composition of the stone. Small stones often pass on their own with hydration and pain management, sometimes helped along with medication that relaxes the ureter. Whether a stone can be dissolved depends on what it is made of. Most calcium-based stones cannot be dissolved and need to pass naturally through the urine. Uric acid stones are the exception, medication prescribed by a doctor can dissolve these over time.
Larger or more stubborn stones may require a procedural approach. Shock wave lithotripsy uses sound waves to break a stone into smaller pieces that can pass more easily. Ureteroscopy involves a thin scope passed through the urinary tract to remove or break up a stone directly, and percutaneous nephrolithotomy, a more involved procedure, is generally reserved for very large stones. A urologist typically determines which approach fits a given case.
If you are dealing with a suspected kidney stone, it is worth consulting a nephrologist or urologist rather than waiting it out. Intense, unbearable pain, fever, or an inability to keep fluids down is a reason to go to the nearest emergency department right away.
How to Prevent Kidney Stones from Recurring
Repeated kidney stones can eventually lead to kidney damage, so prevention matters as much as treatment. Drinking plenty of water, generally enough to keep urine pale, is the single most effective habit for most patients, along with paying attention to diet.
Patients who are especially prone to stones are sometimes advised to add citrus-based, alkaline beverages, like water with lemon or lime, since citrate, a compound in citrus fruit that binds to calcium in the urine, can help reduce new stone formation. Limiting foods high in oxalate, a naturally occurring compound found in foods like spinach and certain nuts that binds with calcium to form stones, can help for calcium oxalate stone formers specifically, while getting calcium from food rather than supplements is often recommended, since dietary calcium can actually bind oxalate in the gut before it reaches the kidneys.
Nephrology or Urology: Who Treats Kidney Stones?
Both specialties are involved in kidney stone care, but they cover different parts of it. Urologists are typically the ones consulted for surgical or procedural removal of a stone that will not pass on its own. Nephrologists focus more on the underlying metabolic causes and long-term prevention, so ongoing stone formers often work with both, one to manage the immediate stone and the other to reduce the odds of the next one.
What Happens If Kidney Stones Keep Coming Back?
For patients who form stones repeatedly, kidney stones stop being a one-time event and become an ongoing part of managing overall kidney health. A nephrologist can order a metabolic evaluation, typically a 24-hour urine collection, to identify exactly what is driving stone formation for that individual patient rather than relying on general prevention advice alone. This can reveal issues like excess calcium excretion, low urine citrate, or elevated oxalate that a standard diet change would not fully address.
Once the underlying pattern is identified, prevention becomes far more targeted, sometimes involving specific medications alongside diet and hydration changes. Regular follow-up imaging may also be recommended for patients with a history of frequent stones, so that new stones can be caught and managed early rather than discovered only once they cause pain.
Frequently Asked Questions
How long does it take to pass a kidney stone?
Small stones often pass within one to three weeks with hydration and pain management. Larger stones can take longer or may need a procedure to help them move, so a doctor’s timeline depends on the stone’s size and position.
Are kidney stones hereditary?
Yes, having a parent or sibling with kidney stones roughly doubles an individual’s risk. Certain rare inherited conditions, like cystinuria, can also make stone formation far more likely from a young age.
Does drinking soda or coffee increase kidney stone risk?
Sugary sodas, particularly those high in fructose, are linked to a higher stone risk, while moderate coffee intake has generally been associated with a lower risk in most studies. Water remains the more reliable choice for prevention either way.
Can kidney stones cause permanent kidney damage?
A single stone that passes without complication rarely causes lasting damage. Repeated stones, a stone that blocks urine flow for an extended period, or an untreated infection alongside a stone can all lead to more serious, sometimes permanent kidney damage.
Talk to ANC About Your Kidney Health
If you or a loved one are dealing with kidney stones or other kidney-related concerns, ANC’s nephrology team can help you get answers and a plan tailored to your situation. Staying hydrated, watching your diet, and getting professional guidance early are the best steps you can take for your kidney health. Contact ANC to schedule a consultation.
Medical Disclaimer
This article is for general educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition. If you believe you are experiencing a medical emergency, call 911 or go to the nearest emergency room immediately.
