What should you know?
Kidney stones are hard deposits made from minerals and salts. A stone may be silent in the kidney but cause severe colicky pain when it enters and obstructs the ureter.
Ultrasound is useful for the kidneys and urinary obstruction, but not every ureteric stone is directly visible. Low-dose non-contrast CT may be selected in appropriate non-pregnant patients.
Common symptoms and signs
- Severe wave-like pain radiating from flank to groin
- Nausea, vomiting and restlessness
- Blood in urine or painful frequent urination
- No symptoms with some small renal stones
Diagnosis and the role of ultrasound
A stone may appear as a bright focus with acoustic shadowing. The key assessment includes hydronephrosis, bladder findings and the opposite kidney.
- Likely stone size and location
- Presence and degree of hydronephrosis
- Renal size and parenchyma
- Ureteric jets in the bladder
Treatment and next steps
Treatment depends on size, location, pain, infection and kidney function. Observation and symptom control may be sufficient, while obstructing or persistent stones can require urologic intervention.
When is urgent care needed?
- Fever or chills with suspected obstruction
- A single functioning kidney, pregnancy or very low urine output
- Uncontrolled pain or repeated vomiting