Signs Your Kidney Stone Is About to Pass: What to Watch For and How to Respond

Understanding Upper Urinary Tract Stones

Stones that form in the kidneys or travel through the ureters are clinically classified as upper urinary tract stones. While many people live with small, asymptomatic kidney stones nestled quietly in the renal pelvis, others experience no discomfort at all—especially when the stone remains stationary and doesn't obstruct urine flow. In fact, up to 80% of small renal calculi (under 4 mm) may pass spontaneously without medical intervention.

When Movement Triggers Acute Symptoms

The real warning signs begin when a stone detaches from the kidney and starts its journey down the narrow ureter—a process often described as "stone migration." As it shifts from the renal pelvis into the ureter, it can become lodged, causing ureteral obstruction and triggering intense, wave-like pain known as renal or ureteral colic.

Classic Pain Patterns: More Than Just Backache

This pain is rarely subtle. It typically strikes suddenly and peaks within minutes—characterized by severe, cramping discomfort in the flank or upper abdomen. Unlike ordinary muscle strain, this pain often radiates downward along the path of the ureter, reaching the groin, testicle (in men), or labia (in women). Many patients describe it as one of the most excruciating experiences they've ever had—sometimes even comparing it to childbirth or a broken bone.

Bladder-Related Symptoms: A Sign the Stone Is Nearing Exit

As the stone approaches the lower end of the ureter—particularly near the ureterovesical junction (where the ureter meets the bladder)—new symptoms may emerge. You might notice increased urinary urgency, frequent trips to the bathroom, or a persistent burning sensation during urination—classic signs of bladder irritation. Some individuals also report sharp, shooting pain extending into the penis or urethra, especially during or immediately after urination.

Blood in the Urine: A Key Diagnostic Clue

Hematuria—blood in the urine—is one of the most common and telling indicators of an active stone passage. In most cases, it's microscopic (visible only under a lab microscope), but roughly 15–20% of patients will notice visible pink, red, or cola-colored urine. While alarming, this symptom alone doesn't indicate infection or serious damage—it's simply evidence that the stone is scraping the delicate lining of the urinary tract.

Systemic Reactions: Why You Might Feel Nauseous or Vomit

Don't dismiss nausea or vomiting as unrelated "stomach flu" symptoms. When a stone blocks urine flow, pressure builds rapidly inside the ureter. This leads to localized swelling, smooth muscle spasm, and reduced blood supply to the area. Because the ureters share nerve pathways with the gastrointestinal tract (via the celiac plexus), your brain may misinterpret the signals—resulting in reflex nausea, vomiting, sweating, or even pallor. These systemic responses often signal significant obstruction and warrant prompt evaluation.

When to Seek Immediate Medical Care

While many stones pass naturally within days, certain red flags require urgent attention: fever or chills (suggesting infection), inability to urinate, unrelenting pain despite over-the-counter medication, or signs of dehydration (e.g., dizziness, rapid heartbeat, dry mouth). Early imaging—such as a non-contrast CT scan—can confirm stone size, location, and degree of obstruction, guiding personalized treatment—from hydration and alpha-blockers to outpatient lithotripsy or surgical removal.