Urine protein (++++) indicates the presence of a large amount of proteinuria, and the patient is more likely to have nephrotic syndrome. Under normal circumstances, a negative urine protein at the time of routine urine examination indicates that less protein is lost from the kidneys. However, if urine protein (++++) is found in the routine urine test, it indicates that the permeability of the filtration membrane of the kidney has been damaged and a large amount of protein is lost from here. In most cases, the presence of large amounts of proteinuria indicates nephrotic syndrome, but of course, nephrotic syndrome is also divided into primary and secondary. Primary nephrotic syndrome has no specific cause, while secondary nephrotic syndrome has specific causes, such as diabetic nephropathy, lupus nephritis, purpura nephritis, ANCA-associated vasculitis, etc. The pathogenesis treatment and prognosis of the above diseases are different, so they need to be carefully identified and then treated from the etiology in order to effectively control urine protein.