A trace or positive protein in urine may indicate which of the following?

• A. Dehydration
• B. Heavy exercise
• C. Kidney damage or disease
• D. All of the above

Answer: (D)

Protein in urine, or proteinuria, means the kidneys are leaking some protein into the urine. A trace or small amount can occur for several reasons, so all of the above is the best answer. Dehydration lowers urine volume and concentrates what’s in the urine, which can make proteins detectable even if there isn’t kidney damage. Heavy exercise can transiently increase glomerular permeability or reduce renal blood flow, leading to short‑lived proteinuria that usually resolves with rest and rehydration. Kidney damage or disease causes lasting protein leakage because the filtering units of the kidney are damaged or not functioning properly. If proteinuria persists, it needs further evaluation to assess for kidney problems.