Causes and Risk Factors for UPJ Obstructions
UPJ is usually present at birth (congenital) and is most frequently diagnosed during a prenatal ultrasound. If undiagnosed after birth, the child may have an abdominal mass or urinary tract infection. When UPJ occurs in older children or adults, it is usually due to scar tissue, abnormalities in muscles under the scar tissue, kidney stones, infection, or previous treatments or surgeries for a blockage. An obstruction also can be caused by compression of the UPJ by a blood vessel or irregularities in the fibrous bands around the ureter.
If undiagnosed or left untreated, chronic UPJ obstruction can lead to significant kidney damage and the gradual loss of kidney function. This is especially true of patients who are diagnosed later in life. Urinary tract infections become common and can be more serious than usual. Kidney stones in the urine that collect in the urinary tract as the result of blockage also become far more common.
Symptoms of UPJ Obstructions
Symptoms of UPJ obstructions include:
- The renal pelvis and/or kidneys are dilated (hydronephrosis)
- Urinary tract infection
- Abdominal mass
- Poor growth in infants (failure to thrive)
- Back pain
- Flank pain