The medical tem for protein in urine is proteinuria, according to WebMD. Proteinuria is defined as an extra amount of protein in a urine sample.
The kidneys act as a filter to remove unneeded materials from the blood while keeping products that the body needs, notes WebMD. This includes proteins. High levels of protein in urine can be caused by temporary conditions or more serious diseases.
Temporary elevations in protein in the urine do not generally signify kidney damage, advises WebMD. These brief increases could be caused by exposure to heat and cold as well as stress, fever, and vigorous exercise. Lasting proteinuria, however, can suggest kidney disease. The cause of this could be a variety of things, including heart disease, lupus or preeclampsia.