About this procedure
Kidney and bladder ultrasound examines kidney size and structure, the urine-collecting system and the bladder. When indicated, it can assess the amount of residual urine left after voiding.
What the examination or consultation can show
This test may show certain cysts, collecting-system dilation, some stones and changes in bladder emptying. It does not measure kidney function by itself and is not a substitute for urine or blood tests.
When an assessment may help
Reasons for examination can include flank or lower-back pain, difficulty urinating, recurrent urinary symptoms, suspected obstruction or monitoring a known finding. A clinician may order a post-void measurement if bladder emptying is in question.
Important limitations and differences
Small stones and parts of the ureters may be difficult to see. An ultrasound report alone cannot establish whether an infection is present or exclude every cause of painful urination. Other tests are chosen according to the clinical picture.
Preparation and procedure
The sonographer scans through the abdomen and flanks, sometimes from the back, then may ask you to urinate before a second bladder image. A moderately filled bladder can help the assessment. Ask how much to drink; do not hold urine until severe pain or alter diuretics without instructions.
Next steps and follow-up
Ultrasound provides an imaging assessment rather than treatment. The findings are interpreted with symptoms, urinalysis, renal function and other investigations when necessary. Follow-up can include an individual urology plan or further imaging.
When to seek urgent care
Severe sudden flank pain with fever or chills, inability to pass urine, vomiting or marked weakness needs urgent medical attention because infection or obstruction may be serious. Call 103 for severe or rapidly worsening symptoms.
Related health information
Pain or burning during urination; Prostatitis; Transrectal prostate ultrasound.
Signs and symptoms
Diagnosis and tests
Care and treatment approaches
When to seek urgent care
Frequently asked questions
Should my bladder be full for the test?
For bladder imaging, filling is often useful; the clinic will specify how to drink based on the examination and your condition.
Will ultrasound always detect kidney stones?
No. Visibility depends on stone size and position. Other imaging may be needed if a stone is still suspected.
What does post-void residual urine mean?
It is the urine remaining after emptying the bladder. The value is interpreted together with symptoms and other measurements.
Important information
A medical consultation is needed for diagnosis and treatment recommendations.
Self-treatment can be harmful to your health.
