Causes:

Investigation

• ultrasound - first-line: identifies presence of hydronephrosis and can assess the kidneys
• IVU- assess the position of the obstruction
• Antegrade or retrograde pyelography- allows treatment
• if suspect renal colic: CT scan (majority of stones are detected this way)

Management

• Remove the obstruction and drainage of urine
• Acute upper urinary tract obstruction: nephrostomy tube
• Chronic upper urinary tract obstruction: ureteric stent or a pyeloplasty