Cholecystitis is an inflammation of the gallbladder that causes episodes of severe abdominal pain. It may be acute or chronic. In most cases, cholecystitis results from a gallstone that obstructs the cystic duct that leads from the gallbladder to the common bile duct, preventing bile from leaving the gallbladder.

In rare cases, patients may develop a serious form of the disorder without gallstones in the gallbladder. This is known as acalculous cholecystitis, and it may result from major injuries, operations, burns, infections and critical illnesses. In particular, acalculous cholecystitis is associated with patients who have received intravenous (I.V.) feedings (total parenteral nutrition) over a long period of time.

Cholecystitis affects women more often than men and is more likely to occur after age 40. Attacks of acute cholecystitis are often triggered by consumption of fatty foods, because bile is needed to digest such foods. During an attack, severe, steady pain (biliary colic) develops in the upper right abdomen, generally grows worse during deep breathing and may extend to the lower right shoulder blade. Over time, the pain may become agonizing.

A physical examination, complete medical history, blood tests, and imaging tests may all be used to diagnose cholecystitis. All forms of cholecystitis are typically treated with surgical removal of the gallbladder (cholecystectomy). In some cases, this surgery is performed right away. In other cases, patients may need to wait until a gallbladder attack subsides and they are healthier before they undergo surgery.