What is a significant indicator of a urinary tract infection?

Blood in urine, also known as hematuria, is a significant indicator of a urinary tract infection (UTI). When the urinary tract is infected, inflammation and irritation can occur, potentially leading to the presence of blood in the urine. This symptom often prompts further investigation, as it can signal an infection or injury within the urinary system, including the bladder and kidneys.

In the context of UTIs, the presence of blood can be particularly concerning, as it may indicate more than just a superficial infection and could necessitate a more thorough evaluation of the urinary tract. The other options, while they could arise from various conditions, are not specific indicators of a urinary tract infection. A high fever might occur in some severe infections, dry mouth can result from dehydration or medications, and joint pain is likely related to other health issues and not directly tied to UTIs. Therefore, blood in urine stands out as a pivotal sign that warrants further medical assessment when a urinary tract infection is suspected.