Hydronephrosis - Cause

Not ready to share? Read other Patient Comments

What was the cause of your hydronephrosis?

Share your story with others:

MedicineNet appreciates your comment. Your comment may be displayed on the site and will always be published anonymously.Patient Comments FAQs

Enter your Comment

Tell us a bit about your background to make your comments more useful to other MedicineNet users. (Optional)

Screen Name: *

Gender of Patient: Male Female

Age Range of Patient:

I am a: Patient Caregiver

* Screen Name will appear next to the published comment. Please do not include your full name or email address.

By submitting your comment, and other materials (collectively referred to as a "Submission") to MedicineNet, you grant MedicineNet permission to use, copy, transmit, publish, display, edit and modify your Submission in connection with its Web site. MedicineNet will not pay you for your Submission. You represent that you have all rights necessary for MedicineNet to use your Submission as set forth above.

Please keep these guidelines in mind when writing your comment:

  • Please make sure you address the question asked.
  • Due to the overwhelming number of comments received, not all comments will be published.
  • When selecting comments to publish, our staff will choose those that are educational and complement the topic. Please try to stay on topic.
  • Your comment may be edited. We would typically edit comments to make them clearer and more readable. We will remove personal information such as last names, email and web addresses, and other potentially harmful information.
  • We will not notify you if your comment has been published. We suggest that you check back on the topic article regularly.
  • We do not provide medical or healthcare advice, treatment, or diagnosis.

Thank you for participating!

I have read and agree to abide by the MedicineNet Terms and Conditions and the MedicineNet Privacy Policy (required).

To prevent our systems from spam, please complete the following prior to submitting your comment.

Please select the white circle:

What causes hydronephrosis?

There are numerous causes of hydronephrosis that are categorized based upon the location of the swelling and whether the cause is intrinsic (located within the urinary collecting system), extrinsic (outside of the collecting system) or if it due to an alteration in function.

Examples of intrinsic causes of hydronephrosis


  • Kidney stone. Likely the most common reason to have unilateral hydronephrosis is a kidney stone that causes obstruction of the ureter. The stone gradually moves from the kidney into the bladder but if it should act like a dam while in the ureter, urine will back up and cause the kidney to swell. This would be classified as an intrinsic obstruction.
  • Blood clot
  • Stricture or scarring


  • Bladder cancer
  • Bladder stones
  • Cystocele
  • Bladder neck contracture


  • The inability to empty the bladder (urinary retention) for any reason may cause bilateral hydronephrosis.
  • Urethral stricture
  • Urethral valves

Examples of extrinsic causes of hydronephrosis


  • Tumors or cancers that compress the ureter and prevent urine flow. Examples include lymphoma and sarcoma, especially if they are located in the retroperitoneum, where the kidneys and ureters are located behind the sac that contains the bowel.
  • Retroperitoneal fibrosis
  • Ovarian vein syndrome
  • Cancer of the cervix
  • Cancer of the prostate
  • Pregnancy
  • Uterine prolapse
  • Scarring due to radiation therapy


  • Prostate hypertrophy or swelling is a common cause of urinary retention and subsequent hydronephrosis in males.
  • Prostate cancer

Examples of functional causes of hydronephrosis


  • Neurogenic bladder or the inability of the bladder to function properly occurs because of damage to the nerves that supply it. This may occur in brain tumors, spinal cord injuries or tumors, multiple sclerosis, and diabetes among other causes.
  • Vesicoureteral reflux where urine flows backwards from the bladder into the ureter. Prenatal hydronephrosis is an example, though it may occur at any time in life.
Return to Hydronephrosis

See what others are saying

Comment from: Sharon B, 65-74 Female (Patient) Published: April 19

My hydroureteronephrosis was caused when I had a large ovarian cyst removed. Unfortunately the blockage was at the site where the ureter connects to the bladder and not caught in time and I lost function of my left kidney.

Was this comment helpful?Yes
Comment from: Shah, 25-34 Female (Patient) Published: May 02

I was diagnosed with ureteropelvic junction (UPJ) obstruction 2 days after having a severe flank pain. I went under robotic pyeloplasty surgery where they remove the scarring tissues and repair the area. I had severe stent pain because my physician did not use the soft silicone based stent for me. I suffered with hydronephrosis 1.5 year because of my surgeon. He removed my stent 7th day after my surgery without replacing it with another. I had recurrent obstruction and my kidney burst and I had bad urine retention all over my back.

Was this comment helpful?Yes


Get the latest health and medical information delivered direct to your inbox!

Health Solutions From Our Sponsors