The definitive diagnosis of cholecystitis mainly involves the following aspects: First, clinical manifestations are crucial. The most common symptoms include nausea, vomiting, abdominal distension, and loss of appetite. Regarding physical examination, there is typically pain in the lower right abdomen and mid-lower right abdomen, with tenderness upon palpation. Furthermore, the onset of cholecystitis is characterized by postprandial pain, particularly after consuming fatty foods or feeling overly full. If these symptoms are present, further examination such as gallbladder ultrasound can be conducted to check for thickening of the gallbladder wall. Additionally, blood tests for inflammatory markers like complete blood count and CRP (C-reactive protein) can be performed. The diagnosis of cholecystitis can be confirmed by combining these symptoms and test results.