First, talk to your doctor. The condition you describe is proteinuria and is usually controlled with an ace inhibitor like lisinopril. Diuretics are usually added to bring the swelling down but they do not control the condition. I had it really bad and meds have completely controlled it for almost 6 years.
Also, while it is a sign of kidney involvement it is not necessarily a sign of imminent kidney failure. But it should not be ignored and your doctor should refer you to a nephrologist who will run tests and might want to take a kidney biopsy to determine what stage your kidneys are in. My condition was bad but early and meds quickly brought it under control.