Protein in Urine

The other day I was at the doctor and had a urine test. He said there was protein in my urine. He then asked me if I had worked out the day before and I said I was in the pool swimming a few hours before that. After that he didn’t seem too concerned but said I would have to come back in.

So what can having protein in my urine mean? I’m not asking what it does mean in my case since I have a doctor, but I would like to understand what problems I may have.

It can mean kidney disease. Diabetic nephropathy causes protein to appear, as does glomerulonephritis, inflammation of the kidney’s filtering units. Exercise can cause transient proteinuria but usually does not mean kidney damage. Many other conditions and exposure can cause protein in the urine.

Most urine specimens which have a trace of protein in them don’t mean kidney disease, and the best course of action is to retest.