(1) No objective findings of impairment of upper urinary tract. Subjective complaints may be present or absent.

(2) Loss of upper urinary function as evidenced by creatinine clearance of 75 to 90 liters/24 hr. (52 to 62.5 ml/min) and PSP excretion of 15 percent to 20 percent in 15 minutes; or if there are intermittent objective findings of upper urinary tract disease or dysfunction not requiring continuous treatment or surveillance.

(3) Loss of upper urinary tract function as evidenced by creatinine clearance of 60 to 75 liters/24 hr. (42 to 52 ml/min) and PSP excretion of 10 percent to 15 percent in 15 minutes; or although function is greater than these levels, there are objective findings of upper urinary tract disease or dysfunction requiring continuous surveillance and frequent symptomatic treatment.

(4) Loss of upper urinary tract function as evidenced by creatinine clearance of 40 to 60 liters/24 hr. (28 to 42 ml/min) and PSP excretion of 5 percent to 10 percent in 15 minutes; or although function is greater than these levels, there are objective findings of mild or moderate upper urinary tract disease or dysfunction which can be only partially controlled.

(5) Loss of upper urinary tract function as evidenced by creatinine clearance below 40 liters/24 hr. (28 ml/min) and PSP excretion below 5 percent in 15 minutes; or although function is greater than these levels there are objective findings of severe upper urinary tract disease or dysfunction which persists despite continuous treatment.