What abnormal finding in a urinalysis may indicate severe renal disease?

The presence of casts in a urinalysis is a significant abnormal finding that may indicate severe renal disease. Casts are formed when urinary proteins precipitate and solidify in the renal tubules, reflecting the health of the kidneys' filtering system. They can take various forms, such as hyaline, granular, or waxy casts, each providing different clues about underlying renal pathology.

For instance, the presence of red blood cell casts typically indicates glomerular injury, while white blood cell casts are often associated with inflammation or infection within the kidneys. The identification of casts in urine can suggest conditions such as acute tubular necrosis, glomerulonephritis, or other significant renal pathology, signaling the need for further evaluation and management.

Other findings in a urinalysis, such as cysts or cocci, relate to different conditions. Cysts may indicate renal cystic diseases but do not specifically reflect acute renal dysfunction. Similarly, the presence of cocci could suggest a urinary tract infection but is not indicative of direct renal damage. Filtration rates are a measure of kidney function rather than a direct finding within a urinalysis itself, and while they can reflect renal disease severity, they do not represent an abnormality found in the urine screening.