How to Tell If a Kidney Stone Has Passed Naturally
Experiencing a kidney stone can be both physically distressing and emotionally overwhelming—but knowing the signs that it's successfully passed can bring immense relief. Unlike many medical conditions, kidney stones often resolve without surgical intervention, especially when they're small enough to travel through the urinary tract. Recognizing the key indicators of stone passage helps patients avoid unnecessary tests, reduce anxiety, and make informed decisions about next steps.
Key Physical Signs That a Kidney Stone Has Passed
Pain subsides significantly—or disappears entirely. One of the most reliable signals is a dramatic reduction or complete resolution of acute flank, back, or lower abdominal pain. During transit, stones irritate the ureter's delicate lining and trigger intense muscular spasms—causing sharp, cramping, or colicky discomfort. When the stone reaches the bladder and exits via urination, this pain typically eases rapidly, sometimes within minutes to hours.
No tenderness upon physical examination. Healthcare providers often assess for costovertebral angle (CVA) tenderness—a sign of kidney irritation—by gently tapping the area where the ribs meet the spine. If this exam yields no discomfort, it supports the likelihood that the stone has moved out of the upper urinary tract. However, clinical evaluation alone isn't definitive—imaging confirmation remains essential.
Confirming Stone Passage: Why Imaging Still Matters
While symptom improvement is encouraging, it should never replace objective diagnostic verification. Even if pain vanishes, residual fragments, silent obstruction, or new stone formation may go unnoticed without imaging. A follow-up ultrasound or low-dose non-contrast CT scan is the gold standard for confirming full clearance—especially in patients with recurrent stones, known anatomical variants, or risk factors like chronic kidney disease or diabetes.
What to Look For in Your Urine
Some people notice visible changes during urination—such as cloudy urine, mild blood-tinged discharge, or even the actual stone itself (often described as gritty, sand-like particles or a small, yellowish-brown pebble). While not everyone sees these signs—and their absence doesn't rule out passage—they can serve as helpful real-world clues when combined with symptom trends.
Do All Kidney Stones Require Treatment?
Not necessarily—and overtreatment can carry risks. Management depends on multiple evidence-based factors:
- Stone size: Stones under 4 mm pass spontaneously in over 80% of cases; those between 4–6 mm have a ~60% chance; stones larger than 6 mm rarely pass without assistance.
- Location: Distal ureteral stones (closer to the bladder) are far more likely to pass than proximal ones near the kidney.
- Symptoms & complications: Asymptomatic kidney stones—even up to 10 mm—may be safely monitored if no hydronephrosis, infection, or functional decline is present.
For example, a small, stable renal calculus with no associated hydronephrosis or pain often warrants only periodic ultrasound monitoring and lifestyle counseling—not immediate intervention. In contrast, an obstructing ureteral stone—even if modest in size—requires prompt evaluation due to its potential to impair kidney function or trigger infection.
Next Steps After Confirming Stone Passage
Once imaging confirms the stone is gone, focus shifts to prevention. Up to 50% of first-time stone formers will experience recurrence within five years without proactive measures. Evidence-backed strategies include increasing daily fluid intake (target: >2 liters of urine output), reducing sodium and animal protein consumption, optimizing calcium intake (from food—not supplements), and, when appropriate, metabolic testing and targeted pharmacotherapy.
Remember: Passing a stone is just the beginning of long-term kidney health. Partnering with a urologist or nephrologist ensures personalized care, reduces future risk, and transforms a painful episode into a powerful opportunity for lasting wellness.