3+ protein in the urine warrents further evaluation. Causes can include simple infections to a variety of kidney disorders (i.e. glmerular disorders, diabetes etc.).
Evaluation would include quantifying the amount of protein that is excreted - most likely during a 24-hr urine collection. Another likely test that would be helpful would be a kidney ultrasound to identify any obvious masses or disorders that may be causing the protein in the urine. If all the tests are negative, a kidney biopsy would be the most conclusive test.
In any case, I would suggest a referral to a nephrologist (kidney specialist) for further evaluation and discussion of the aforementioned tests.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.