Renal diseases will affect the normal handling of proteins leading in many cases to an increased concentration of protein in the urine. Other diseases, such as urinary tract infections, and diabetic kidney disease, can also affect the amount of protein present in the urine.From what I can establish I *think* they can diagnose what caused the increase from the TYPE of protein that is present in increased levels.
http://www.healthcentral.com/mhc/top/00358...results%20mean: Factors that can change the level of protein in urine: Severe emotional stress Strenuous exercise Radiopaque contrast media within 3 days of the urine testDrugs that can increase measurements include acetazolamide, aminoglycosides, amphotericin B, cephalosporins, colistin, griseofulvin, lithium, methicillin, nafcillin, nephrotoxic drugs (such as arsenicals, gold salts), oxacillin, penicillamine, penicillin G, phenazopyridine, polymyxin B, salicylates, sulfonamides, tolbutamide, and viomycin.