Yes, you can have a kidney stone and feel nothing at all, and it happens more often than most people think. Many people only learn about theirs when a scan for something unrelated happens to show it.1PubMed Central. Pathophysiology and Symptoms of Renal Colic in Children – a Case Report But having no pain describes where the stone is right now. It isn’t a promise about the future.
How Common Silent Kidney Stones Are
When healthy adults with no symptoms were screened with low-dose CT, about 8 in 100 had at least one stone.2PubMed. Prevalence of urolithiasis in asymptomatic adults: objective determination using low dose noncontrast computerized tomography Those stones were usually small, about 3 mm on average, and people often had two or more.3PubMed. Prevalence of urolithiasis in asymptomatic adults: objective determination using low dose noncontrast computerized tomography Among people getting CT scans for other reasons, the number was lower: about 3 in 100 had a stone found by chance, slightly more often in men.4PubMed Central. The Prevalence of Incidentally Detected Urolithiasis in Subjects Undergoing Computerized Tomography
Looking at stones rather than people, among those found on ultrasound, roughly 3 to 5 in 10 had caused no symptoms.5PubMed Central. Asymptomatic nephrolithiasis detected by ultrasound Stones spotted on scans of the belly done for other complaints were silent about 7 times in 10.6PubMed Central. Asymptomatic nephrolithiasis detected by ultrasound A scan often finds a stone that has been there for years, so a report that mentions one doesn’t mean it formed recently or that any recent symptoms come from it.
Why a Kidney Stone Can Cause No Pain
A stone sitting still inside the kidney and not blocking anything can stay completely silent.7Chennai’s Premier Hospital For Treatment of Kidney Stones – Laser Kidney Stones Clinic. Can You Have Kidney Stones Without Any Pain at All? The kidney collects urine in small cup-shaped spaces. A stone resting in one has room around it, and urine flows past.
Trouble starts when a stone drops into the ureter, the much narrower tube from kidney to bladder, and blocks urine. The ureter squeezes to push urine along, and that squeezing against a blockage causes the wave-like pain people describe. That’s why even a large stone can be painless if it doesn’t block drainage.8PubMed Central. A silent, giant staghorn calculus managed with open surgery: a case report
Pain rises sharply once a stone is slightly wider than the inside of the ureter, about 7.5% to 20% wider.9Journal of Applied Mechanics. Quantification of Ureteral Pain Sensation Induced by Kidney Stone Beyond that, a bigger stone adds only a little more pain.10Journal of Applied Mechanics. Quantification of Ureteral Pain Sensation Induced by Kidney Stone A large stone resting in the kidney can be painless while a small one lodged in the ureter can be severe. That’s why a doctor looks at the stone’s position and also at whether the kidney shows swelling from backed-up urine.
Some symptoms get missed rather than being absent. Some stone symptoms mimic a urinary tract infection, so people may shrug them off as temporary discomfort.11Michigan Institute of Urology. 6 Common Signs of Kidney Stones, Besides Pain A stone called silent may sometimes have caused mild signs nobody linked to it. These include pink, red, or brown urine from small amounts of blood, a dull ache in the side or back that comes and goes, burning or frequent urination, and cloudy or strong-smelling urine.
Will a Silent Stone Start Causing Problems
In one group of people watched over time, about 28 in 100 silent kidney stones went on to cause symptoms.12PubMed. The natural history of nonobstructing asymptomatic renal stones managed with active surveillance Stones in the upper or middle part of the kidney caused symptoms more often than those in the lowest part, about 4 in 10 versus 2.4 in 10.13PubMed. The natural history of nonobstructing asymptomatic renal stones managed with active surveillance Upper and middle stones were also more likely to pass on their own, about 15 in 100 versus 3 in 100.14PubMed. The natural history of nonobstructing asymptomatic renal stones managed with active surveillance Stones low in the kidney sit at the bottom, where gravity keeps them put. They are less likely to move into the ureter, so less likely to hurt, but also less likely to pass, so they tend to stay.
Across studies, the share that became painful ranged widely, from under 1 in 10 to over 7 in 10.15PubMed. The Durability of Active Surveillance in Patients with Asymptomatic Kidney Stones: A Systematic Review Stones grew in anywhere from 5 in 100 to two-thirds of people, depending on the study.16PubMed. The Durability of Active Surveillance in Patients with Asymptomatic Kidney Stones: A Systematic Review
If a silent stone starts moving, the pain is usually sudden and sharp in the side or back, often spreading to the groin. It comes in waves, and you can’t get comfortable. Nausea, vomiting, or blood in the urine can come with it. Fever or chills with this pain need same-day care, as they can mean infection behind a blockage.
The quieter risk is damage without pain. A silent stone can harbour bacteria, grow, or slowly block drainage from the kidney.17NU Hospitals. Asymptomatic Kidney Stones: Are They Dangerous? Kidney function can then be lost without any symptoms, which is why stones are checked rather than ignored.18NU Hospitals. Asymptomatic Kidney Stones: Are They Dangerous? Even a staghorn stone, a large branching stone filling much of the kidney, can be completely painless.19PubMed Central. A silent, giant staghorn calculus managed with open surgery: a case report Specialists argue that silent staghorn stones are not truly harmless and that removing them is safer for the kidney.20PubMed. The case for a more aggressive approach to staghorn stones21PubMed Central. Spontaneous Radiological Disappearance of a Large Staghorn Calculus in an Atrophic Kidney With One Percent Function
At a check-up of a watched stone, doctors mainly compare its size, its position, and whether the kidney shows swelling from blocked drainage. They also ask about any pain, blood in the urine, or urinary infections since the last visit. A stone that is the same size and not blocking anything is generally reassuring, while growth or swelling usually prompts a conversation about treatment.
Treat It or Watch It
For small stones in the kidney that aren’t blocking anything, guidelines allow watching instead of treating.22PubMed Central. Urological Guidelines for Kidney Stones: Overview and Comprehensive Update That advice rests on weak evidence, since how these stones behave isn’t well pinned down.23PubMed Central. Urological Guidelines for Kidney Stones: Overview and Comprehensive Update So doctors use active surveillance, meaning regular scans to check size and symptoms.24PubMed Central. Urological Guidelines for Kidney Stones: Overview and Comprehensive Update European guidelines suggest a first check at 6 months, then yearly, using ultrasound or X-ray.25PubMed Central. Urological Guidelines for Kidney Stones: Overview and Comprehensive Update Being watched doesn’t push people toward surgery over time; longer monitoring didn’t raise the share who ended up having it.26PubMed. The Durability of Active Surveillance in Patients with Asymptomatic Kidney Stones: A Systematic Review
Removal is often advised when a stone grows, blocks the kidney, causes infection, pain or blood in the urine, or is larger than 15 mm.27PubMed Central. Urologists’ opinion on treating asymptomatic stones: Would we treat ourselves as we treat our patients? Survey from European Association of Urology, Young Academic Urologists, Endourology and Urolithiasis working party Other health conditions, your preference, or your social situation can tip the balance toward treatment.28PubMed Central. Urologists’ opinion on treating asymptomatic stones: Would we treat ourselves as we treat our patients? Survey from European Association of Urology, Young Academic Urologists, Endourology and Urolithiasis working party People in jobs where a sudden attack is dangerous, such as pilots, long-haul truckers, frequent travellers, and military members, are often offered treatment promptly.29Nature Reviews Urology. When (and how) to surgically treat asymptomatic renal stones If your work or travel would make a stone attack risky, tell your doctor.
Treatment varies with the stone. Shock waves from outside the body can break stones into passable pieces. A thin scope passed up through the bladder can reach and break stones. Larger stones may need a small keyhole procedure through the back. The choice depends on size, location, and your health.
When deciding, it helps to ask how big the stone is and exactly where in the kidney it sits, and whether it is blocking any drainage. Ask how often you’ll be scanned and with what kind of scan, and what would change the recommendation from watching to treating.
How Accurate Kidney Stone Scans Are
A CT scan, a detailed X-ray scan, finds kidney stones far more reliably than ultrasound. In one comparison, ultrasound found about 3 in 4 stones that CT confirmed.30PubMed Central. Limitations of ultrasound compared with computed tomography for kidney stone surveillance In another, ultrasound missed roughly half of stones in the right kidney and more in the left.31PubMed. Accuracy of sonography for detecting renal stone: comparison with CT In people with an overactive parathyroid gland, CT found stones in nearly 4 times as many people as ultrasound did.32PubMed Central. “Silent” kidney stones in “asymptomatic” primary hyperparathyroidism—a comparison of multidetector computed tomography and ultrasound
Ultrasound also tends to make stones look bigger than they are, about 9 mm versus 5.5 mm on CT on average.33PubMed Central. Limitations of ultrasound compared with computed tomography for kidney stone surveillance The overestimation is worse for small stones and in people with higher body weight.34PubMed Central. Limitations of ultrasound compared with computed tomography for kidney stone surveillance If a decision depends on exact size, ask whether CT should confirm it; guidelines recommend CT before any treatment.35PubMed Central. Urological Guidelines for Kidney Stones: Overview and Comprehensive Update Doctors still use ultrasound because it involves no radiation, which matters for repeated checks, and it’s cheap and widely available.
Your scan report usually lists stone size in millimetres and states which kidney and which part, upper, middle, or lower. If your report mentions hydronephrosis, that means swelling from blocked drainage, which is important to ask about.
Keeping a Silent Stone From Growing
People with stones are usually offered tests to find why they form, plus advice on diet and fluids.36PubMed Central. Removal of Small, Asymptomatic Kidney Stones and Incidence of Relapse Having a passed or removed stone analysed shows what it’s made of, which guides prevention. Stones are made of different materials, such as calcium oxalate or uric acid, and the best steps differ between them. A silent stone that stays in the kidney can’t be analysed this way, so doctors rely on urine and blood tests for clues. Ask whether that workup makes sense for you.
Drinking enough to make about 2 to 2.5 litres of urine a day is the most effective general step. Pale yellow urine through the day is a good sign. Drink more in hot weather or after exercise, and spread drinks across the day, including the evening.
Cutting back on salt and not overdoing animal protein helps reduce stone-forming minerals in urine. Cutting calcium-rich foods usually backfires, as normal dietary calcium helps prevent common stones, so avoiding all dairy isn’t recommended for most people. Citrus drinks like lemon water may help with some stone types.