What does urine protein mean by one plus one minus?

A plus or minus sign of urine protein indicates that protein is detectable in urine, but in small amounts.

Normally protein should not be present in urine. When kidney problems occur, kidney filtration is impaired, causing protein to leak out of urine, resulting in proteinuria. A plus or minus sign of urine protein indicates a slight increase in protein content in urine, but not enough to be diagnosed as proteinuria. This is common in early kidney diseases such as glomerulonephritis and nephrotic syndrome.

When a plus or minus sign of urine protein is detected, other tests should be performed to determine the cause, such as physical examination, renal function test, renal ultrasound examination, renal magnetic resonance imaging, etc.