Chronic cholecystitis clinically manifests as recurrent dull pain in the upper abdomen and biliary colic, which the patient can quickly relieve on their own; acute cholecystitis involves more severe pain that cannot be relieved without intervention, and is usually accompanied by fever, nausea, and vomiting. In chronic cholecystitis, pressing on the right upper abdomen elicits no special reaction; in acute cholecystitis, pressing on the right upper abdomen causes obvious pain, known as a positive Murphy's sign. Acute cholecystitis is accompanied by a significant increase in white blood cells, and an ultrasound can reveal a marked enlargement and thickening of the gallbladder wall; chronic cholecystitis does not show these specific characteristics.