Which laboratory finding is a key indicator of pyuria in urinalysis?

The presence of leukocytes in urine is a key indicator of pyuria. Pyuria refers to the presence of pus or an increased number of white blood cells (WBCs) in the urine, which typically indicates an infection or inflammation in the urinary tract. In urinalysis, a high leukocyte count suggests that the body is responding to an infectious process, such as a urinary tract infection (UTI).

Leukocytes can be detected in the urine through a microscopic examination or can be indicated by a positive leukocyte esterase test, which signifies the breakdown of WBCs in the urine. Therefore, identifying leukocytes during urinalysis is crucial for diagnosing conditions related to pyuria.

The other options mentioned do not directly indicate pyuria. The presence of crystals may suggest issues related to different types of kidney stones but does not necessarily indicate an infection. The presence of glucose in urine is often associated with conditions such as diabetes but is not relevant to pyuria. Lastly, bilirubin in the urine typically points towards liver dysfunction or hemolysis rather than an inflammatory response in the urinary tract.