Unilateral hydronephrosis is swelling of one kidney due to a backup of urine.

See also:  Bilateral hydronephrosis

Hydronephrosis is a condition that occurs with a disease and is not a disease itself. Treatment and prognosis for unilateral hydronephrosis depend what is causing the kidney swelling.

Conditions that are often associated with unilateral hydronephrosis include:

• Acute unilateral obstructive uropathy
• Chronic unilateral obstructive uropathy
• Vesicoureteric reflux (backflow of urine from bladder to kidney)
• Nephrolithiasis (kidney stones)
• Hydronephrosis that occurs without a known cause during pregnancy

Unilateral hydronephrosis occurs in approximately 1 in 100 people.

• Flank pain
• Abdominal mass
• Nausea and vomiting
• Urinary tract infection
• Fever
• Dysuria
• Increased urinary frequency
• Increased urinary urgency

Unilateral hydronephrosis is usually identified with tests such as the following:

• Intravenous pyelogram (IVP)
• Isotope renography (radio-isotope scan of the kidneys)
• Ultrasound of the kidneys or abdomen
• CT scan of the kidneys or abdomen
• Abdominal MRI