What could cause transient proteinuria in a patient’s urine?

Transient proteinuria can occur due to temporary physiological conditions such as stress, fever, or rigorous exercise. These factors can lead to an increase in protein levels in the urine without indicating any underlying kidney disease. For example, during intense physical activity, muscle breakdown and increased metabolism can result in a temporary rise in the proteins excreted in urine. Stress and fever can also affect protein levels as they might lead to changes in glomerular permeability or alterations in renal blood flow.

In contrast, chronic kidney disease and diabetic nephropathy are associated with persistent proteinuria due to ongoing damage or dysfunction in the kidneys. Acute renal failure may present with proteinuria, but it typically indicates a more serious and lasting renal impairment. Therefore, while those conditions are significant, they are not responsible for the transient nature of the proteinuria seen in situations like exercise or acute stress.