Hydronephrosis

Overview

Hydronephrosis is the swelling of a kidney due to a build-up of urine. It happens when urine cannot drain out from the kidney to the bladder from a blockage or obstruction. Hydronephrosis can occur in one or both kidneys. The main function of the urinary tract is to remove wastes and fluid from the body.

Symptoms

Urinary tract infections commonly occur in people with vesicoureteral reflux. A urinary tract infection (UTI) doesn't always cause noticeable signs and symptoms, though most people have some.

These signs and symptoms can include:

• A strong, persistent urge to urinate
• A burning sensation when urinating
• The need to pass small amounts of urine frequently
• Cloudy urine
• Fever
• Pain in your side (flank) or abdomen

As your child gets older, untreated vesicoureteral reflux can lead to:

• Bed-wetting
• Constipation or loss of control over bowel movements
• High blood pressure
• Protein in urine

Treatment

Treatment for hydronephrosis depends on the underlying cause. Although surgery is sometimes needed, hydronephrosis often resolves on its own.

• Mild to moderate hydronephrosis. Your doctor may opt for a wait-and-see approach to see if you get better on your own. Even so, your doctor may recommend preventive antibiotic therapy to lower the risk of urinary tract infections.
• Severe hydronephrosis. When hydronephrosis makes it hard for the kidney to function — as can happen in more-severe hydronephrosis or in hydronephrosis that involves reflux — surgery may be recommended to fix a blockage or correct reflux.
• Left untreated, severe hydronephrosis can lead to permanent kidney damage. Rarely, it can cause kidney failure. But hydronephrosis typically affects only one kidney and the other kidney can do the work for both

Diagnosis

Your health care provider may refer you to a doctor who specializes in conditions affecting the urinary system (urologist) for your diagnosis.

Tests for diagnosing hydronephrosis may include:

• A blood test to evaluate kidney function
• A urine test to check for signs of infection or urinary stones that could cause a blockage
• An ultrasound imaging exam, during which your doctor can view the kidneys, bladder and other urinary structures to identify potential problems
• A specialized X-ray of the urinary tract that uses a special dye to outline the kidneys, ureters, bladder and urethra, capturing images before and during urination

If necessary, your doctor may recommend additional imaging exams, such as a CT scan or MRI. Another possibility is a test called a MAG3 scan that evaluates function and drainage in the kidney.

When to see a doctor

Contact your doctor right away if your child develops any of the signs or symptoms of a UTI, such as:

• A strong, persistent urge to urinate
• A burning sensation when urinating
• Abdominal or flank pain

Call your doctor about fever if your child:

• Is younger than 3 months old and has a rectal temperature of 100.4 F (38 C) or higher
• Is 3 months or older and has a fever of 100.4 F (38 C) or higher and seems to be ill
• Is also eating poorly or has had significant changes in mood

Causes

Your urinary system includes your kidneys, ureters, bladder and urethra. All play a role in removing waste products from your body via urine.

Tubes called ureters carry urine from your kidneys down to your bladder, where it is stored until it exits the body through another tube (the urethra) during urination.

Vesicoureteral reflux can develop in two types, primary and secondary:

• Primary vesicoureteral reflux. Children with primary vesicoureteral reflux are born with a defect in the valve that normally prevents urine from flowing  backward from the bladder into the ureters. Primary vesicoureteral reflux is the more common type.
• As your child grows, the ureters lengthen and straighten, which may improve valve function and eventually correct the reflux. This type of vesicoureteral reflux tends to run in families, which indicates that it may be genetic, but the exact cause of the defect is unknown.
• Secondary vesicoureteral reflux. The cause of this form of reflux is most often from failure of the bladder to empty properly, either due to a blockage or failure of the bladder muscle or damage to the nerves that control normal bladder emptying.

Risk factors

Risk factors for vesicoureteral reflux include:

• Bladder and bowel dysfunction (BBD). Children with BBD hold their urine and stool and experience recurrent urinary tract infections, which can contribute to vesicoureteral reflux.
• Race. White children appear to have a higher risk of vesicoureteral reflux.
• Sex. Generally, girls have a much higher risk of having this condition than boys do. The exception is for vesicoureteral reflux that's present at birth, which is more common in boys.
• Age. Infants and children up to age 2 are more likely to have vesicoureteral reflux than older children are.
• Family history. Primary vesicoureteral reflux tends to run in families. Children whose parents had the condition are at higher risk of developing it. Siblings of children who have the condition also are at higher risk, so your doctor may recommend screening for siblings of a child with primary vesicoureteral reflux.

Complications

Kidney damage is the primary concern with vesicoureteral reflux. The more severe the reflux, the more serious the complications are likely to be.

Complications may include:

• Kidney (renal) scarring. Untreated UTIs can lead to scarring, which is permanent damage to kidney tissue. Extensive scarring may lead to high blood pressure and kidney failure.
• High blood pressure. Because the kidneys remove waste from the bloodstream, damage to your kidneys and the resultant buildup of wastes can raise your blood pressure.
• Kidney failure. Scarring can cause a loss of function in the filtering part of the kidney. This may lead to kidney failure, which can occur quickly (acute kidney failure) or may develop over time 

Is hydronephrosis serious in pregnancy?

Most cases do not cause problems for the fetus. For most babies born with prenatal hydronephrosis, their condition resolves over time and they require no treatment to pass urine normally. But more serious cases of prenatal hydronephrosis can result in urinary tract infections, scarring or permanent kidney damage.

What is the main cause of hydronephrosis?

Hydronephrosis is usually caused by a blockage in the urinary tract or something disrupting the normal workings of the urinary tract. The urinary tract is made up of the kidneys, the bladder, the ureters (the tubes that run from the kidney to the bladder) and the urethra (the tube that carries urine out of the body).

Who is at risk for hydronephrosis?

At-risk groups for hydronephrosis are infants, men over age 50 (due to prostate enlargement), pregnant women, sexually active women (due to an increased likelihood of urinary tract infections), and persons with a history of kidney stones.

What fruit is good for kidneys?

Pineapple, cranberries, red grapes, and apples are all kidney-friendly fruits with anti-inflammatory properties.