Kidney stones typically do not cause symptoms while they form within the kidney. If the stone passes into the ureter – the narrow tube that connects the kidneys to the bladder – it may cause pain if/when it gets lodged in the tube. Pain caused by a kidney stone may change to a different location or increase in intensity as the stone moves through your ureter. The pain from the stone is not from it moving down the ureter, but rather from the blockage it is causing, thereby reducing the kidney's ability to drain properly. Therefore, the pain may lessen or disappear when the stone changes location within the ureter to a position where it is not blocking the flow of urine from the kidney towards the bladder.
Common Symptoms and Signs That You May Experience Include:
- Severe pain in the side and back that comes in waves and fluctuates in intensity
- Pain that may radiate to the lower abdomen and groin
- Nausea and vomiting
- Pain with urination
- Pink, red, or brown urine
- Persistent urge to urinate
- Fever and chills if an infection is present
- Cloudy or foul-smelling urine if infection is present
In many instances, pain from passing a stone will occur suddenly. Patients should contact their physician right away when this occurs.
Immediate medical attention is required when pain is:
- So severe that a comfortable position can not be found
- Increasing despite analgesics
- Accompanied by nausea and vomiting
- Accompanied by fever and chills
In many instances, your doctor may instruct you to go to the emergency room for prompt evaluation. In addition to detailed history, including family history of stone disease and past history of stone passage, the basic investigation into a patient who is passing a stone are:
- Vital signs, including temperature, blood pressure, and heart rate
- Urinalysis, including urine pH and urine culture
- Serum blood counts to assess for possible infection
- Serum electrolytes (calcium, phosphate, bicarbonate, uric acid)
- Blood urea nitrogen, serum creatinine (renal function)
Radiologic investigation (options):
Unenhanced helical computed tomography (no dye) is the best imaging method to confirm the diagnosis of a urinary stone in a patient with acute flank pain. The accuracy is greater than 95%. It also gives specific information about the density of the stone and the location, which helps guide the physician with treatment options.
Ultrasound (sonogram) has the advantage of having no associated radiation but it is less accurate in the acute setting. It can be used to monitor the kidney and the stone during attempted passage.
Plain abdominal x-ray (KUB – Kidney/Ureter/Bladder) is important to assess the radio-opacity of the stone, to monitor stone progression, and to determine potential therapy.
In a patient with recurrent stones, in addition to the baseline investigations, a 24-hour urine assessment should be done for urine volume and calcium, oxalate, uric acid, citrate, urine sodium, and creatinine excretion. Urine creatinine is measured to determine the accuracy of urine collection. This is not done during the acute management of a stone, but rather afterwards to try to optimize fluid intake and dietary adjustments to prevent recurrent stones from forming.