Hydronephrosis: Causes, Symptoms, Treatment and Diagnosis

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Hydronephrosis: Causes, Symptoms, Treatment and Diagnosis

  • Category

    Urology

  • Published By

    GetWellGo Team

  • Updated on

    13-Jun-2025

What is hydronephrosis?

Hydronephrosis is a condition where the one or both kidneys swell up because of the accumulation of urine. It occurs when there is blockage or obstruction in the urinary tract that does not allow urine to drain normally from the kidney to the bladder.

Hydronephrosis causes

Hydronephrosis is a condition where the urine is unable to drain adequately from the kidney into the bladder, and the kidney becomes swollen. The etiology can be divided into location (obstructive vs non-obstructive), duration (acute vs chronic), and age group (infants vs adults).

Major Causes of Hydronephrosis

Obstruction in the Urinary Tract

These are the most frequent causes:

Kidney stones

  • Prevent urine flow from the kidney to the bladder.

Ureteral stricture

  • Ureter narrowing due to trauma, surgery, or inflammation.

Tumors (benign or malignant)

  • In the kidney, ureter, bladder, or nearby areas compressing on the urinary tract.

Benign prostatic hyperplasia (BPH) – in males

  • Compresses on the urethra and blocks the flow of urine.

Bladder outlet obstruction

  • Caused by tumors, stones, or functional issues.

Vesicoureteral Reflux (VUR)

  • Urine moves in a backward direction from the bladder to the ureters and kidneys.
  • Common in infants and children, usually diagnosed with a VCUG test.

Pregnancy

  • The expanding uterus may press the ureters, particularly the right one.
  • Typically temporary and improves after childbirth.

Congenital (At Birth)

Ureteropelvic junction (UPJ) obstruction

  • Obstruction where the ureter joins the kidney.

Posterior urethral valves (in male babies)

  • Tissue folds in the urethra that impede urine flow.

Neurogenic Bladder

  • Nerve dysfunction (e.g., in spinal cord injury, multiple sclerosis, or diabetes) may cause incomplete emptying of the bladder, resulting in backflow.

Ureterocele

  • A balloon-like distension of the lower ureter within the bladder, usually congenital, which obstructs flow of urine.

Post-Surgical or Post-Radiation Changes

  • Fibrosis or inflammation from operations or pelvic radiation can obstruct the urinary tract.

Hydronephrosis symptoms

Hydronephrosis symptoms vary from mild to severe and may either be dependent on whether the condition is chronic or acute (gradual or sudden), as well as whether one or both kidneys are involved.

Adult Symptoms

  • Pain in flank or back
  • Typically on the same side as the involvement
  • Sharp or dull
  • Painful abdomen or pressure
  • Dysuria (painful urination)
  • Frequent urination
  • Trouble urinating or failure to empty
  • Hematuria (blood in urine)
  • Nausea and vomiting
  • Fever and chills (if infected)
  • Cloudy or odor urine

Infant and Child Symptoms

  • Unexplained fever
  • Poor feeding
  • Fussiness or crying during urination
  • Vomiting
  • Abdominal distention
  • Failure to gain weight
  • Can be seen prenatally on ultrasound

Hydronephrosis treatment

Hydronephrosis treatment is aimed at eliminating the root cause of the urine obstruction and maintaining kidney function. The technique used is based on:

  • Severity (mild, moderate, or severe)
  • Its acute or chronic nature
  • Underlying cause (e.g., stone, tumor, pregnancy)
  • Patient's age and general health

Treat the Root Cause

Kidney Stones

  • Small stones: Can pass spontaneously; increased fluids + pain medications.

Large or obstructed stones:

  • Ureteroscopy
  • Lithotripsy (ESWL) – shatters the stone with sound waves
  • Percutaneous nephrolithotomy (for extremely large stones)

Infection (e.g., pyelonephritis or UTI)

  • Antibiotics to manage infection
  • Drainage may be required if infection is associated with blockage

Tumors or Prostate Enlargement

  • Surgery, chemotherapy, or radiation (depending on type)
  • Prostate treatment (e.g., medications or TURP surgery)

Pregnancy-related Hydronephrosis

  • Generally resolves after delivery
  • Pain management and observation unless complications develop

Congenital Blockages (in children)

  • Observation if mild and kidney function is normal
  • Surgery (such as pyeloplasty) if obstruction is severe or kidney function deteriorates

Relieve the Obstruction (Drainage Procedures)

Employed when urine cannot drain spontaneously:

Ureteral stent

  • Small tube inserted into the ureter to maintain patency

Nephrostomy tube

  • Tube inserted directly into the kidney to drain urine out of the body

Ongoing Monitoring (If Mild)

  • Ultrasound or CT scans to monitor kidney size and function
  • Blood tests (such as creatinine, BUN)
  • Watchful waiting can be applied during pregnancy or in mild conditions

Hydronephrosis in adults

Adult hydronephrosis is the inflation of a single or both kidneys with urine due to urine accumulation when there is a blockage or inadequate flow within the urinary tract. It's either acute (sudden) or chronic (insidious), and may occur in one (unilateral) or both kidneys (bilateral).

Hydronephrosis in pregnancy

Hydronephrosis in pregnancy is the enlargement of the kidney because of the accumulation of urine when its passage is being partially obstructed. It is a frequent condition during pregnancy and is normally physiological (normal) in nature but not pathological.

How Common Is It?

  • Occurs in up to 90% of pregnant women, particularly in the second and third trimesters.
  • More frequent on the right side owing to the position of the uterus and anatomical variations in the ureters.

Causes of Hydronephrosis during Pregnancy

Physiological

  • Hormonal changes: Progesterone causes relaxation of muscles of the ureters, reducing the flow of urine.
  • Uterine pressure: The expanding uterus presses against the ureters, particularly on the right side.

Pathological

  • Kidney stones
  • Urinary tract infections (UTIs)
  • Ureteral obstruction secondary to other causes

Hydronephrosis diagnosis

Hydronephrosis is diagnosed by imaging tests that show dilation (enlargement) of the renal pelvis and calyces, usually in conjunction with clinical symptoms or signs. Diagnosis seeks to establish the diagnosis and determine the cause of urinary tract obstruction.

Step-by-Step Diagnostic Approach

Medical History and Physical Exam

  • Symptoms: Flank pain, urinary symptoms, fever, etc.
  • Risk factors: Kidney stones, recent surgeries, pregnancy, history of UTIs
  • Physical exam may include:
  • Flank tenderness
  • Palpable kidney (rare)

Imaging Studies (Mainstay of Diagnosis)

Ultrasound (US)

  • First-line test
  • Identifies kidney swelling and severity
  • No radiation—safe in pregnancy and children

CT Scan (Non-contrast if stones suspected)

  • More detailed than ultrasound
  • Best for identifying:
  • Kidney stones
  • Tumors
  • Ureteral obstruction
  • Used if the ultrasound is unclear or complications are suspected

MRI / MR Urography

  • Alternative to CT if radiation has to be avoided
  • Especially helpful in pregnancy

Intravenous Pyelogram (IVP)

  • Earlier method; seldom used nowadays
  • X-ray imaging following an injection of dye to outline urinary tract

Urine Tests

Urinalysis:

  • Seek blood, white blood cells, bacteria, or protein
  • Urine culture:
  • When infection is suspected
  • 24-hour collection of urine (in selected situations):
  • To assess stone risk

Blood Tests

  • Creatinine and Blood Urea Nitrogen (BUN):
  • Gauge kidney function

Electrolytes:

  • Check for imbalance due to decreased kidney function

Nuclear Renal Scan (Renography)

  • Reviews function of each kidney
  • Used to estimate severity of obstruction
  • Usually employed in chronic or complicated cases

Hydronephrosis surgery

Surgery may be necessary for hydronephrosis if there is a chronic or severe obstruction of the urinary tract, particularly if kidney function is in jeopardy or symptomatology is severe. The surgery varies with the cause, location of obstruction, and whether acute or chronic.

Surgical Choices:

Ureteral stent placement

  • Indication: Short-term bypassing of obstruction and enabling urine drainage from kidney to bladder.
  • Method: Thin plastic tube inserted within the ureter.

Used in:

  • Stones
  • Tumors
  • Inflammatory obstruction
  • Typically inserted endoscopically (cystoscopy) with anaesthesia.

Percutaneous Nephrostomy

  • Purpose: Relieves urine by draining directly from kidney to outer bag.
  • Method: Catheter inserted through the skin into renal pelvis.

Used when:

  • Ureter fully obstructed
  • Acute drainage is required (e.g., infection, sepsis)
  • Often temporary measure prior to definitive surgery.

Pyeloplasty

  • Purpose: Ureteropelvic junction (UPJ) obstruction repair.

Method:

  • Excise narrowed segment
  • Reconnect healthy segments
  • Approach: Open, laparoscopic, or robotic-assisted
  • Long-term solution, particularly in congenital or chronic conditions

Ureteral Reimplantation

  • Purpose: Repair obstruction or reflux at bladder end of ureter.
  • Method: Reattach ureter to a new location on the bladder.
  • Used in children with vesicoureteral reflux or narrowing of ureter

Stone Removal Procedures

If hydronephrosis is caused by kidney or ureteral stones, these can be removed surgically:

  • Ureteroscopy with laser lithotripsy
  • Percutaneous nephrolithotomy (PCNL) for large stones
  • Shock wave lithotripsy (SWL) (non-invasive)

Tumor Resection or Bypass

For cancer or extrinsic compression (e.g., due to a tumor in the pelvis), options are:

  • Tumor removal
  • Ureteral bypass
  • Palliative stenting or nephrostomy if surgery is not feasible

Hydronephrosis complications

  • Kidney Damage or Kidney Failure
  • Recurrent Urinary Tract Infections (UTIs)
  • Urosepsis
  • Kidney Stones
  • Hypertension (High Blood Pressure)
  • Electrolyte Imbalances
  • Urinary Incontinence or Retention
  • Pain and Discomfort

Ureteral obstruction and hydronephrosis

Ureteral obstruction is one of the main reasons for hydronephrosis. It happens when there is an obstruction in the flow of urine from the bladder to the kidney, resulting in urine accumulation and kidney swelling (hydronephrosis).

What Is Ureteral Obstruction?

  • Blockage or constriction of the ureter (the tube that leads each kidney to the bladder), which cuts off normal drainage of urine.

How It Causes Hydronephrosis

When the ureter becomes blocked:

  • The urine is not able to drain normally from the kidney.
  • Urine collects in the renal pelvis (the drainage component of the kidney).
  • It leads to increased pressure, enlargement, and swelling — the signature of hydronephrosis.

Why Choose GetWellGo for Hydronephrosis Treatment?

GetWellGo is regarded as a leading supplier of healthcare services. We help our foreign clients choose the best treatment locations that suit their needs both financially and medically.

We offer:

  • Complete transparency
  • Fair costs.
  • 24 hour availability.
  • Medical E-visas
  • Online consultation from recognized Indian experts.
  • Assistance in selecting India's top hospitals for hydronephrosis treatment.
  • Expert urologist/nephrologist with a strong track record of success
  • Assistance during and after the course of treatment.
  • Language Support
  • Travel and Accommodation Services
  • Case manager assigned to every patient to provide seamless support in and out of the hospital like appointment booking
  • Local SIM Cards
  • Currency Exchange
  • Arranging Patient’s local food
     

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