What can cause transient proteinuria?

Transient proteinuria is a temporary increase of protein in the urine, often seen under certain physiological conditions rather than as a result of a pathologic state. Exercise is a well-known cause of transient proteinuria because vigorous physical activity can lead to increased muscle metabolism and, subsequently, the release of proteins into the urine. This phenomenon is usually seen in athletes or individuals who participate in intense workouts and generally recovers after a period of rest.

In contrast, thyroid issues, dehydration, and renal disease typically indicate a more chronic or significant alteration in bodily function or health status that could lead to persistent proteinuria. Thyroid dysfunction can affect various body systems but does not directly cause transient proteinuria. Dehydration may increase the concentration of urine, but it does not inherently lead to the presence of significant protein levels. Renal disease generally results in persistent proteinuria as it reflects underlying kidney damage or dysfunction. Thus, exercise stands out as the factor that can lead to a temporary and reversible increase in urine protein levels.