Understanding the Most Common Symptoms of Kidney Stones: Pain, Bleeding, and Beyond

What Are Kidney Stones—and Why Do They Cause Such Distressing Symptoms?

Kidney stones—also known as renal calculi or urolithiasis—are solid mineral and salt deposits that form inside the kidneys. While small stones may pass unnoticed, larger ones can trigger a cascade of uncomfortable and sometimes alarming symptoms. Recognizing these signs early is key to prompt diagnosis, effective treatment, and preventing complications like urinary obstruction or kidney damage.

The Two Primary Symptom Categories: Severe Pain and Visible Blood in Urine

1. Intense, Location-Dependent Pain—Often the First Red Flag

Pain from kidney stones isn't uniform—it shifts in intensity and location as the stone travels through the urinary tract. This "moving pain" is one of the most telling clinical clues:

• Dull, persistent flank discomfort: When a stone remains lodged in the kidney or renal pelvis, it often causes a vague, deep ache in the back or side (flank area). Though less dramatic than other forms, this low-grade pain may linger for days and be mistaken for muscle strain or gastrointestinal issues.

• Sudden, excruciating colicky pain: As the stone enters the narrow ureter—the tube connecting the kidney to the bladder—it triggers powerful, wave-like contractions. This results in ureteral colic: sharp, cramping pain that peaks within minutes, radiates toward the groin or inner thigh, and may cause nausea, vomiting, and restlessness. Over 80% of patients describe this as the worst pain they've ever experienced—even more intense than childbirth or a broken bone.

• Lower abdominal and pelvic pressure with painful urination: Once the stone reaches the distal ureter near the bladder junction, pain often localizes to the lower abdomen or pubic region. Many individuals also report dysuria—a burning or stinging sensation during urination—as the stone irritates the urethral opening or bladder neck.

2. Hematuria—When Your Urine Turns Pink, Red, or Brown

Blood in the urine—hematuria—is another hallmark sign. It occurs when the rough, jagged edges of a passing stone scrape against delicate urinary tract tissues, causing microscopic or visible bleeding.

In many cases, hematuria is microscopic (detectable only under a microscope or via urine dipstick testing), but up to 40% of patients notice gross hematuria: urine that appears pink, cola-colored, or even bright red. While alarming in appearance, visible blood doesn't always correlate with stone size—it's more about how much irritation the stone causes along its path.

When Infection Enters the Picture: Fever, Chills, and Systemic Warning Signs

If a kidney stone blocks urine flow—and especially if bacteria are present—a serious complication called obstructive pyelonephritis can develop. This infection requires urgent medical attention and may present with:

• High fever (often above 101.5°F / 38.6°C) and drenching night sweats• Profound chills or shaking rigors• Cloudy, foul-smelling urine• Increased urgency, frequency, or suprapubic pressure

Left untreated, infected urinary obstruction can rapidly progress to sepsis—a life-threatening systemic response. If you experience fever alongside classic stone symptoms, seek emergency care immediately.

Why Early Recognition Matters—And What to Do Next

Not all kidney stones require surgery—but all deserve evaluation. Mild cases may resolve with hydration, pain control, and alpha-blocker medications (like tamsulosin) to relax the ureter. Larger or impacted stones may need lithotripsy, ureteroscopy, or minimally invasive procedures.

If you're experiencing recurrent flank pain, unexplained hematuria, or urinary symptoms that worsen over hours—not days—don't wait. A simple non-contrast CT scan remains the gold standard for diagnosis, offering rapid, accurate imaging without radiation concerns for most adults.