In 5% of cases, bile inspissation (due to dehydration) or bile stasis (due to trauma or severe systemic illness) can block the cystic duct, causing an acalculous cholecystitis
in most cases (90%), it is caused by complete cystic duct obstruction usually due to an impacted gallstone in the gallbladder neck or cystic duct, which leads to inflammation within the gallbladder wall.
It develops in up to 10% of patients with symptomatic gallstones.
Acute cholecystitis is acute gallbladder inflammation, and one of the major complications of cholelithiasis or gallstones.
