Kidney stones are small, hard deposits of mineral and acid salts that crystallize within the urine. While they form in the kidney, they cause intense, wave-like pain (renal colic) when they move into the narrow urinary tract. This discomfort arises as the stone attempts to pass through the ureter, often creating a temporary obstruction. Safely managing this process requires understanding when to attempt self-management and when immediate medical attention is necessary. This guide identifies steps for promoting conservative stone passage and specific warning signs for professional intervention.
Immediate Steps for Conservative Stone Passage
Aggressive fluid intake is the first practical step in encouraging a small stone to pass. The goal is to significantly increase urine production, creating pressure to propel the stone toward the bladder. Aiming for a urine output of at least two liters per day maintains a continuous, high-volume flow beneficial for smaller stones. However, during an acute obstruction, hydration should be steady rather than overwhelming, as excessive fluid intake may temporarily increase pressure and worsen pain.
Controlling pain and inflammation is equally important to facilitate passage. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are preferred for renal colic because they serve a dual purpose. NSAIDs relieve pain and simultaneously reduce the inflammation and swelling that constrict the ureter around the stone. Reducing this swelling physically opens the passageway, making it easier for the stone to move.
For stones larger than five millimeters, Medical Expulsive Therapy (MET) may be prescribed to increase spontaneous passage. This therapy typically involves alpha-blocker medications, like tamsulosin, which relax the smooth muscles of the ureter. Relaxing these muscles, particularly in the lower ureter, widens the tube’s diameter. This allows the stone to traverse the final, narrow segments more easily.
Once acute pain subsides, moderate physical activity can support the passage process. Simple movement, such as walking or climbing stairs, uses gravity and internal motion to help dislodge the stone. Finally, strain all urine using a specialized strainer or coffee filter until the stone has passed completely. Capturing the stone allows a physician to analyze its composition, which is fundamental for determining preventive measures against future stone formation.
Recognizing Signs That Require Emergency Care
While small stones often pass spontaneously, certain symptoms signal a severe complication requiring immediate emergency medical care. The presence of fever, especially when accompanied by chills, is a serious red flag. Fever with a kidney stone may indicate a urinary tract infection has developed behind the obstruction, which can rapidly progress to life-threatening sepsis.
Uncontrolled pain unresponsive to prescribed or over-the-counter medication is another reason to seek immediate professional help. Intractable pain suggests a high-grade obstruction or a stone too large to pass, causing intense pressure within the kidney. Persistent, severe nausea and vomiting are also concerning, as they prevent proper oral hydration, leading to rapid dehydration and electrolyte imbalance.
A complete inability to urinate (anuria) or a sudden, significant decrease in urine output is a medical emergency. This indicates a complete blockage of the urinary tract, which causes pressure buildup and can lead to acute kidney injury. This is particularly concerning for individuals with only one functioning kidney, as blockage results in immediate renal failure.
Medical Procedures for Unpassable Stones
When a stone is too large, causes a persistent blockage, or is associated with infection, medical intervention is necessary. Stones larger than 10 millimeters rarely pass spontaneously and are candidates for active removal. The choice of procedure depends on the stone’s size, location within the urinary tract, and the patient’s overall health status.
Extracorporeal Shock Wave Lithotripsy (ESWL) is a non-invasive procedure using targeted, high-energy sound waves delivered from outside the body. These shock waves fragment the stone into smaller, sand-like pieces that the patient passes naturally in the urine. ESWL is generally most effective for stones located in the kidney or upper ureter, typically measuring less than 15 millimeters.
Ureteroscopy (URS) is a common, highly effective, minimally invasive procedure performed under anesthesia. A small, flexible scope is inserted through the urethra and advanced up the ureter to the stone. The physician uses a laser fiber to break the stone into fragments or a miniature basket to remove the stone whole. URS often provides higher stone-free rates than ESWL, especially for stones in the middle and lower ureter.
In cases of acute obstruction with signs of infection, a temporary ureteral stent may be placed immediately. A stent is a thin, hollow tube inserted into the ureter to bypass the stone, ensuring urine drains from the kidney to the bladder and relieving dangerous pressure. Stent placement is often a temporizing measure, allowing acute symptoms to resolve before a definitive stone removal procedure, such as URS, is safely performed later.