Which symptom is a key indicator of appendicitis?

A key indicator of appendicitis is an elevated white blood cell (WBC) count, typically seen as 20,000 or higher. This increase in WBC count reflects the body's immune response to inflammation and infection, which often occurs in appendicitis due to the obstruction of the appendix leading to a buildup of bacteria. The elevated WBC count is a critical piece of laboratory evidence that supports the diagnosis, as it indicates that there may be an ongoing inflammatory process in the abdominal region.

The other symptoms presented do not align with common presentations of appendicitis. Severe diarrhea is more characteristic of gastrointestinal infections or inflammatory bowel diseases rather than appendicitis. Increased urination is often associated with urinary tract issues or conditions affecting bladder function rather than appendicitis. Chest pain typically suggests issues related to the heart or lungs, not the gastrointestinal tract, and is not indicative of an appendiceal problem. Therefore, the elevation of WBC count stands out as the most relevant and significant symptom for diagnosing appendicitis.