Not Medical Advice: A gallstone stuck in the cystic duct, a tube that carries bile from the gallbladder, is most often the cause of sudden (acute) cholecystitis, an inflammation of the gallbladder. The gallstone blocks fluid from passing out of the gallbladder. This results in an irritated and swollen gallbladder. Infection or trauma, such as an injury from a car accident, can also cause cholecystitis.
Acute acalculous cholecystitis, though rare, is most often seen in critically ill people in hospital intensive care units. In these cases, there are no gallstones. Complications from another severe illness, such as HIV or diabetes, cause the swelling.
Long-term (chronic) cholecystitis is another form of cholecystitis. It occurs when the gallbladder remains swollen over time, causing the walls of the gallbladder to become thick and hard.
The most common symptom of cholecystitis is pain in your upper right abdomen that can sometimes move around to your back or right shoulder blade. Other symptoms include:
Nausea or vomiting.
Tenderness in the right abdomen.
Fever.
Pain that gets worse during a deep breath.
Pain for more than 6 hours, particularly after meals.
Older people may not have fever or pain. Their only symptom may be a tender area in the abdomen.
To learn more about cholecystitis, see WebMD.