Kidney stones are dense mineral deposits that form inside the urinary tract, notorious for causing severe pain. This pain, called renal colic, is usually the first sign that a stone is trying to pass through the urinary system. While standard symptoms are localized to the flank and groin, generalized, systemic symptoms like fever, chills, and body aches are not normal. These widespread symptoms are not caused by the stone-passing process itself, but they represent a serious complication requiring immediate medical attention.
Understanding the Standard Symptoms of Kidney Stones
The defining symptom of an uncomplicated kidney stone is acute, severe pain known as renal colic. This pain originates from the stretching of the kidney’s capsule caused by urine backup and the forceful contractions of the ureter trying to push the stone along. The discomfort typically begins in the flank or back region and often shifts, radiating toward the lower abdomen and groin as the stone moves down the ureter.
The intense pain frequently triggers secondary symptoms like nausea and vomiting, which are related to the pain severity, not systemic infection. Another common indication is hematuria, or blood in the urine, resulting from the stone irritating the urinary tract lining. The urine may also become cloudy or have a foul odor, and a person may experience increased urgency or pain when urinating due to the stone’s proximity to the bladder.
The Critical Link: Obstruction and Systemic Infection
Flu-like symptoms, such as high fever, shaking chills (rigors), and profound malaise, are evidence of a severe infection complicating the stone’s presence, not caused by the stone itself. A stone lodged in the ureter creates a blockage, preventing the normal flow of urine from the kidney to the bladder. This obstruction causes urine to back up into the kidney, a condition called hydronephrosis, which rapidly increases pressure.
This stagnant, pressurized urine provides an ideal environment for bacteria to multiply rapidly. When this bacterial infection takes hold within the kidney, it results in a serious condition known as pyelonephritis. The body’s inflammatory response to this bacterial invasion leads to the systemic symptoms often mistaken for the flu, as the infectious agents circulate throughout the body.
Identifying Flu-Like Symptoms as a Urological Emergency
The presence of flu-like symptoms, specifically a fever above 100.4°F (38°C) or uncontrollable shaking chills, in someone with kidney stone pain signals an infected, obstructed kidney. This constitutes a urological emergency, medically termed obstructive pyelonephritis, which carries a significant risk of developing into urosepsis. Urosepsis is a life-threatening systemic blood infection that can lead to organ dysfunction and a drop in blood pressure.
Immediate intervention is necessary to relieve the obstruction and drain the infected urine, as antibiotics alone cannot clear the infection without drainage. Urgent treatment involves intravenous broad-spectrum antibiotics and a procedure to decompress the kidney. Decompression is often achieved by placing a temporary stent inside the ureter to bypass the stone or by inserting a nephrostomy tube through the back to drain the built-up urine externally. Delaying this drainage increases the risk of severe, potentially fatal outcomes.