A shadow on the gallbladder is a term used in abdominal imaging. Common causes include gallbladder stones, cholecystitis, etc. A definitive diagnosis requires a CT scan, etc. 1. Gallbladder stones: Gallbladder stones are common in adults, and the stones are divided into mainly cholesterol or cholesterol-based mixed, melanin stones. Most people have no obvious symptoms, and biliary colic is a typical symptom of gallbladder stones. Ursodeoxycholic acid is commonly used for lithotripsy, and if conservative treatment is ineffective, laparoscopic cholecystectomy can be used. 2. Cholecystitis: Cholecystitis is a chemical inflammation that occurs when the gallbladder duct is blocked and bile is stagnant due to gallstones. Cholecystitis often occurs at night, with pain radiating to the right shoulder and sudden attacks after eating fatty foods. Treatment consists of anti-infection with aminobenzylpenicillin and choleretic treatment with 50% magnesium sulfate. If conservative treatment fails, cholecystectomy can be performed under minimally invasive laparoscopy. When patients experience discomfort, they should go to the hospital immediately, and medications need to be applied appropriately as prescribed by the doctor.