The causes of stomach pain in hepatocellular carcinoma patients may be the stimulation of liver peritoneum by cancer tumor, complication of cholecystitis, spontaneous peritonitis and hepatocellular carcinoma bleeding, as follows: Firstly, cancer tumor stimulates liver peritoneum: patients with hepatocellular carcinoma will generally have stomach pain in the middle and late stages, mainly as vague pain in the right upper abdomen, which is one of the very common clinical manifestations of hepatocellular carcinoma. Secondly, complication of cholecystitis: the mass in liver tissue will compress and block the intrahepatic bile duct system and cause acute cholecystitis, which is manifested as severe colic pain in the right upper abdomen and may be accompanied by vomiting and jaundice. Thirdly, spontaneous peritonitis: When liver cancer patients reach advanced stage, they will usually have a large amount of peritoneal fluid, which will easily complicate spontaneous peritonitis, manifesting as pain in the whole abdomen with obvious rebound pain after pressure. Due to the tension of abdominal muscles, the so-called plate-like abdomen will also appear, i.e. the abdomen becomes hard, like a plank. Fourthly, hepatocellular carcinoma bleeding: if the liver cancer mass grows too big, it will rupture and bleed. If the blood breaks into the abdominal cavity, it will lead to sudden severe abdominal pain, accompanied by hemorrhagic shock symptoms, and the patient may die quickly. If the bleeding occurs under the liver envelope and does not enter the abdominal cavity, the patient will also have obvious abdominal pain, but the pain may be relieved gradually.