Ureteral stone

Disease Description (Causes and Symptoms)

• Definition summary: A ureteral stone is a condition that occurs when a crystal (stone) in urine formed in the kidneys becomes lodged in or moves through the ureter, which connects the renal pelvis to the bladder.
• Causes and pathophysiology: When urine becomes concentrated or the concentration of certain substances (calcium, oxalate, uric acid, etc.) increases, crystals form, remain in the urinary tract, and become stones. Risk factors include inadequate fluid intake, a high-salt or high-protein diet, certain metabolic abnormalities (hypercalciuria, hyperuricosuria, etc.), family history, and hot environments (dehydration).
• Main symptoms: Severe flank pain, radiating pain (men: lower abdomen, testicles, scrotum; women: vulva), hematuria, nausea and vomiting, urinary frequency and painful urination, and abdominal bloating. If fever or chills occur, a urinary tract infection (with a risk of sepsis) is suspected.

Treatment Methods

• Acute-phase treatment
  • Pain control: Nonsteroidal anti-inflammatory drugs (NSAIDs) are first-line; short-term analgesics (prescribed by a doctor) may be used in combination if necessary.
  • When infection is present: Antibiotics are administered based on urinalysis and culture results. If urinary obstruction and infection occur together, emergency drainage (stent insertion or renal pelvic drainage) is necessary.
• Facilitating stone passage (conservative treatment)
  • Observation for spontaneous passage: Depending on the stone’s size and location, it may be possible to wait for spontaneous passage (smaller stones are more likely to pass). Adequate fluid intake is recommended, and passage-assisting medications such as alpha-blockers (e.g., tamsulosin) may be used at the healthcare provider’s discretion.
• Procedures and surgery
  • Extracorporeal shock wave lithotripsy (ESWL): Shock waves are applied externally to fragment the stone and facilitate spontaneous passage. Suitability depends on the stone’s size, location, and composition.
  • Ureteroscopic laser lithotripsy and stone fragment removal: A small endoscope is used to directly fragment and remove the stone in the ureter.
  • Percutaneous nephrolithotomy (PCNL): Used for large kidney stones or when access to the ureter is difficult.
  • Ureteral stent insertion: Used for immediate drainage to relieve urinary obstruction or in cases of infection.
  • Open or laparoscopic surgery: Rarely necessary.
• Lifestyle management and preventive medication
  • Adequate fluid intake (target daily urine volume of approximately 2–2.5 L; individual needs may vary).
  • Dietary management: Limit salt, limit excessive animal protein, avoid excessive intake of foods high in oxalate (spinach, chocolate, nuts, etc.), and maintain an appropriate intake of dietary calcium (excessive calcium restriction may actually increase risk). If uric acid stones are suspected, limit purines.
  • Medication: If stones recur or a specific metabolic abnormality is identified, a doctor may prescribe medication (e.g., uricosuric or uric acid-lowering agents, calcium excretion inhibitors, or citrate supplements).
• Precautions
  • Seek emergency medical care immediately in cases of high fever, chills, severe vomiting, little or no urine output, or suspected acute deterioration of kidney function.
  • During pregnancy, imaging and treatment methods are selected with consideration for the safety of the mother and fetus (adjusted toward relatively safe methods).

Checklist Before an Outpatient Visit (Including Sample Questions)

• Items/information to prepare and provide
  • A list of all medications currently being taken (including prescriptions, OTC medicines, and supplements) and any allergy history
  • Medical history: Previous urinary stones, surgical history, kidney disease, gout, etc.
  • Recent test results (if possible, imaging data (DICOM/CD) or test reports) — abdominal CT, plain urinary tract radiographs, urinalysis, and blood test results
  • Symptom record: When the pain started, its location and intensity, whether it radiates, presence or absence of hematuria, fever, chills, or vomiting, and changes in urine volume
  • Lifestyle information: Usual fluid intake, dietary habits (protein and salt intake), and occupation (such as outdoor work)
• Items to show the doctor during the outpatient visit
  • Recent urinalysis results (whether pyuria, hematuria, or bacteriuria is present) and urine culture results (if available)
  • If you have had stones in the past, stone analysis results (if available)
• Tests that may be performed during the outpatient visit
  • Noncontrast abdominal CT (relatively high sensitivity and specificity), urinary tract ultrasound (to check for hydronephrosis), urinalysis and blood tests, and, if necessary, a 24-hour urine test (in cases of recurrent stones)

Examples of General Questions to Ask the Doctor

• "What are the size and location of the stone now, and how likely is it to pass spontaneously?"
• "Do any medications I take (or illnesses I have) affect stone treatment or passage?"
• "What lifestyle and dietary changes do you recommend to reduce recurrence?"

Examples of Disease-Specific Questions

• "Can the composition of the stone (calcium, uric acid, struvite, etc.) be determined? If so, would the preventive medication or dietary recommendations change?"
• "Based on my current pain and urinalysis results, is there a possibility that an emergency procedure (such as stent insertion or ureteroscopy) will be necessary?"

(Note) Emergency symptoms: If high fever or chills, low blood pressure or decreased consciousness, inability to urinate or a sharp decrease in urine output, uncontrollable pain, or similar symptoms occur, immediate evaluation in an emergency department is recommended.