Fever. Fever is the most common cause of proteinuria (up to 75% of febrile patients). If severe, it may be associated with an increase in hyaline casts (etiology unknown, possibly dehydration). Cystitis-urethritis. Cystitis and urethritis are lower urinary tract infections, often hard to differentiate from renal infection. Clumping of WBCs is suggestive of pyelonephritis but […]