A temporary elevation of protein in urine can be caused by cold exposure, emotional stress, fever, heat exposure or strenuous exercise, explains Mayo Clinic. The causes of persistent elevation include amyloidosis, certain drugs, diabetes, hypertension and Goodpasture’s syndrome.
Other diseases that cause high urine protein levels are chronic kidney disease, heart disease, heart failure and glomerulonephritis, according to Mayo Clinic.
The presence of high amounts of protein in the urine is called proteinuria, and it can be a sign of kidney disease, states WebMD. Normal kidneys retain most of the protein that passes through them, and protein leaks out into the urine when the kidneys are damaged. Proteinuria is not a specific disease, and treatment involves managing the underlying cause. The progression of kidney damage in patients with diabetes and hypertension is managed with ACE inhibitors or ARBs.