Which urinary sediment component is defined as a high concentration of red blood cells?

The term that specifically describes a high concentration of red blood cells in the urine is hematuria. Hematuria signifies the presence of red blood cells, which can be detected through urinalysis, often leading to further investigation to determine the underlying cause. This condition may result from various factors, including urinary tract infections, kidney stones, or trauma to the urinary system.

Casts, on the other hand, are formed from proteins secreted by renal tubules and often contain cells, including red blood cells, but their presence indicates specific renal pathology rather than a straightforward measurement of red blood cell concentration. Crystals are solid precipitates formed from urinary solutes and typically reflect metabolic processes rather than assessing red blood cell presence. Artifacts refer to irregularities or contaminants in a urine sample that do not stem from bodily processes or conditions, further distinguishing them from the pathological significance of hematuria.