Which of the following is a common symptom of urinary tract infections?

A burning sensation during urination is a hallmark symptom of urinary tract infections (UTIs). This symptom arises due to irritation and inflammation of the urinary tract lining because of the infection. When bacteria invade the urinary tract, they can cause inflammation in the bladder and urethra, leading to discomfort, particularly during urination, which is often described as a burning sensation.

In contrast, severe flank pain typically indicates kidney involvement or a more serious condition, such as pyelonephritis, rather than a common UTI. Increased appetite is not associated with UTIs, as the immune response and symptoms of infection often do not promote a desire to eat. Similarly, weight gain is unrelated to UTIs and may result from entirely different health issues. Therefore, the burning sensation during urination represents a specific and commonly experienced symptom in individuals with urinary tract infections.