Are there different types of VUR?
VUR is one condition. There are not different types of VUR but there are different grades. VUR is divided into five grades of severity1:
- Grade I: The mildest form of VUR. Urine enters the ureter but does not travel all the way up to the kidney. The ureters look normal in size.
- Grade II: The urine travels all the way up the ureter and enters the part of the kidney where urine is collected before it drains to the ureter (renal pelvis). The ureters and renal pelvis appear normal in size.
- Grade III: Similar to grade II except the ureters and/or the renal pelvis appear abnormal in size or shape.
- Grade IV: Similar to Grade III except the ureter is grossly enlarged.
- Grade V: The most severe form of VUR. It is similar to grade IV, except the ureter is also twisted and curved. The renal pelvis is also enlarged and its normal structural details are no longer detectable.
There is another distinction used to describe VUR. Since we all have two kidneys and two ureters entering our bladders (some people have four ureters, two on each side), VUR can affect one side (unilaeral VUR) or both sides (bilateral VUR).
- Jacobson SH, Hansson S, Jakobsson B.Vesico-ureteric reflux: occurrence and long-term risks. Acta Paediatr Suppl 1999; 88: 22-30.)