What this finding means
Hydronephrosis is dilation of the kidney's collecting system. A persistent obstruction to urine drainage can gradually damage kidney tissue. However, dilation on imaging does not itself prove significant ongoing obstruction: further assessment is needed. The terms pyelectasis and hydronephrosis in imaging reports must be interpreted alongside the clinical picture.
Causes include a stone, narrowing of the ureter or its junction with the renal pelvis, scarring after a procedure, or external compression. A congenital abnormality may first become apparent in adulthood. The plan will therefore differ for a stone, postoperative narrowing and impaired patency of the ureteropelvic junction.
Pain may be episodic, mild or absent. The absence of pain alone does not show that kidney function is preserved. If dilatation was found incidentally, consultation is still necessary, especially with a solitary kidney or changes on both sides.
When you should not wait for a routine appointment
Fever and chills with impaired urinary drainage may indicate an infection in an obstructed kidney. This requires urgent assessment in hospital; drainage sometimes needs to be restored immediately.
- Seek urgent care for fever with lower back pain, especially if you have a known stone or hydronephrosis.
- Do not wait if urine output stops or falls sharply, particularly if you have only one kidney.
- Severe pain that does not respond to treatment, repeated vomiting, marked weakness or confusion require urgent care. If the condition is severe, call 103 or 112.
What to establish before choosing treatment
Ultrasound shows dilation and the condition of kidney tissue. CT or MR urography, when indicated, helps clarify the anatomy and the level of obstruction. To determine how well each kidney works and how urine drains from it, the doctor may request dynamic renal scintigraphy with a diuretic challenge.
Blood tests assess overall kidney function, but do not always reflect each kidney's contribution separately. Results are interpreted together with symptoms and changes over time: one number or one image cannot replace this assessment. The examination method is selected with kidney function, pregnancy, previous contrast administration and other limitations in mind.
Observation, drainage or treatment of the cause
Monitoring is possible when investigations show no dangerous drainage impairment or loss of function and the situation is stable. It requires an agreed follow-up date and clear warning signs for seeking help sooner.
An infection with obstruction, or a threat to kidney function, may require drainage through a ureteral stent or nephrostomy. This allows urine to flow out but does not necessarily remove the cause. Further treatment is selected separately: stone removal, correction of a narrowing, or another approach based on the established diagnosis. The indications for, and availability of, a specific procedure are discussed after the test results have been reviewed.
What to bring to the urologist
Bring previous and recent ultrasound, CT or MRI studies with the actual images, renal scintigraphy results if performed, available creatinine results and urine tests. After surgery, bring the discharge summary and procedure report. If you have a stent or nephrostomy, bring the insertion date and the follow-up plan you were given.
You do not need to complete every listed test before the first visit. Appointments with urologist Artem Vladimirovich Ershov: RZD Medicine, 47 Lomonosova Street, Krasnoyarsk; contact center +7 (391) 229-22-22.
Before your appointment
Frequently asked questions
Does hydronephrosis always require surgery?
No. The decision depends on confirmed impaired drainage, kidney function, symptoms and changes during follow-up. The size of the renal pelvis alone does not determine the indication for treatment.
If creatinine is normal, does that mean the kidney is definitely unaffected?
Not necessarily. If only one kidney is affected, the other can maintain the overall result. When needed, each kidney's function is assessed separately.