Early Warning Signs and Sensations When Passing a Kidney Stone

Passing a kidney stone is rarely subtle—and understanding the body's signals can significantly reduce anxiety, speed up medical intervention, and even prevent complications. The journey of a kidney stone out of the body occurs in two key anatomical phases: first, from the renal pelvis into the ureter, and second, from the ureter into the bladder (and eventually out through the urethra). Recognizing what happens at each stage helps patients distinguish between mild discomfort and urgent warning signs that require immediate care.

Phase 1: Stone Still in the Kidney — Often Silent, But Not Always

When a stone remains nestled in the renal pelvis or calyces, many people experience no symptoms at all—especially if the stone is small (<5 mm) and not obstructing urine flow. Others report only vague, low-grade sensations: a dull, persistent ache in the flank or back, occasional pressure beneath the ribs, or intermittent discomfort after physical activity or dehydration. These subtle cues are easily mistaken for muscle strain or digestive upset—but they may signal the early presence of a stone forming or beginning to shift.

Phase 2: Stone Enters the Ureter — The Onset of Acute Symptoms

Once the stone dislodges and enters the narrow ureter, pressure builds rapidly. This triggers ureteral colic—a hallmark sign of active stone passage. Unlike typical back pain, this pain is typically sudden, severe, and wave-like, peaking within minutes and often lasting 20–60 minutes per episode. It commonly starts in the flank or upper abdomen and radiates downward along the path of the ureter—into the lower abdomen, groin, and sometimes even the inner thigh or genital area (testicle in men, labia in women).

What Else to Watch For: Beyond Pain

Hematuria (blood in the urine) is another frequent red flag—often visible as pink, red, or cola-colored urine, though it may only show up under microscopic analysis. This occurs not because the stone itself bleeds, but because its jagged edges scrape and irritate the delicate ureteral lining during movement.

Nausea and vomiting are also extremely common—not just due to pain, but because the ureters and intestines share nerve pathways (via the celiac plexus). As ureteral pressure rises, it activates these shared nerves, triggering gastrointestinal distress—even without any stomach-related issue.

Final Stretch: Stone Nears the Bladder — New Symptoms Emerge

As the stone approaches the distal ureter—specifically the intramural segment where the ureter passes through the bladder wall—patients often develop bladder irritation symptoms. These include frequent urination, urgency (a sudden, compelling need to void), painful or burning urination (dysuria), and a sensation of incomplete bladder emptying. Some men describe sharp, shooting pain at the tip of the penis; women may feel localized pressure or stinging near the urethral opening. These signs strongly suggest the stone is nearing exit—and may pass spontaneously within hours to days.

While most small stones (<6 mm) pass on their own with supportive care—hydration, NSAIDs, and time—seek emergency help if you experience fever, chills, inability to urinate, or persistent vomiting. These could indicate obstruction, infection (pyelonephritis), or other serious complications requiring prompt urologic evaluation.