Stretching or dilation of the urinary tract may occur because of a blockage to the flow of urine, which causes increased pressure “up stream,” and leads to urine building up above the point of blockage.
Hydronephrosis can also occur due to an abnormal connection between the ureter and bladder that allows urine to flow backward toward the kidney when the bladder contracts to empty. This condition is known as reflux.
Sometimes hydronephrosis can be caused by a blockage that has cleared and left the urinary system stretched but not under any pressure.
How is Hydronephrosis Diagnosed?
Medical advances in prenatal ultrasound examinations have helped identify large numbers of infants with urinary dilation or stretching prior to birth. In diagnosing hydronephrosis, Nemours urologists may recommend a voiding cystourethrogram (VCUG) and a renal (kidney) scan.
The VCUG tells us if the “one-way” valve in the bladder is functioning, while the renal scan reveals how well the kidneys are functioning and assesses how fast the urine drains from the kidney into the bladder to see if a blockage exists. These studies help determine if surgical repair or immediate treatment is needed since hydronephrosis can lead to urinary tract infections (UTIs) and sometimes permanent kidney damage.
A urine protein test measures the total amount of protein in the urine. Once a urine sample is collected, the lab determines the amount of protein in the urine sample. This test is often done as part of a routine urinalysis in which several chemicals in the urine are measured.
Why It's Done
In most healthy people, the kidneys prevent significant amounts of protein from entering the urine, so the urine protein test is most commonly used to screen for kidney disease. It's also used to monitor kidney function in kids already diagnosed with kidney disease or who are taking medications that can affect the kidneys.
Abnormal results also may point to diseases affecting other parts of the body. Other tests may be needed before a definite diagnosis can be made.
Before the test, your child might need to temporarily stop taking specific drugs that could interfere with results. Be sure to discuss this with your doctor.
Collecting the specimen should only take a few minutes. Your child will be asked to urinate into a clean sample cup in the doctor's office. If your child isn't potty trained and can't urinate into a cup, a small catheter may need to be inserted into the bladder to obtain the urine specimen.
Alternatively, a urine collection bag with adhesive tape on one end might be used to collect a sample from an infant. You'll clean your baby's genital area and then arrange the bag around the urinary opening. Once the bag is in place, you'll secure it with the attached tape. You can then put a diaper on your baby. Remove the collection bag once your baby has urinated into it, usually within an hour. Deliver this specimen to the lab.
If you take the specimen at home, follow any storage and transportation instructions the lab gives you.
What to Expect
Because the test involves normal urination, there shouldn't be any discomfort as long as your child can provide a urine specimen.
Getting the Results
The results of the urine protein test should be available within a day. Your doctor will go over the results with you and explain what they mean. If the results are abnormal, further tests may be ordered.
No risks are associated with taking a urine protein test. Infants may occasionally experience skin irritation from the adhesive tape on the collection bag. If a catheter is used to obtain the urine, it may cause temporary discomfort. If you have any questions or concerns about this procedure, talk to your doctor.
Helping Your Child
The urine protein test is painless. Explaining how the test will be conducted and why it's being done can help ease any fear. Make sure your child understands that there should be no foreign matter, such as toilet paper or hair, in the sample.
If You Have Questions
If you have questions about the urine protein test, speak with your doctor.