Advanced pancreatic cancer may vomit blood. Pancreatic cancer is a malignant tumor of the digestive tract with insidious onset, rapid progression, and very poor therapeutic outcome and prognosis. If the pancreatic cancer lesion is large or the lymph nodes are large and involve the duodenum. Penetrating the duodenal mucosa may cause the patient’s upper gastrointestinal bleeding, resulting in vomiting blood and other conditions. Pancreatic cancer patients with poor nutritional status may have coagulation dysfunction; in addition, patients with advanced pancreatic cancer may have bone marrow suppression during chemotherapy, such as platelet decline, which may cause patients with coagulation dysfunction resulting in vomiting blood. In addition, pancreatic cancer can invade the bile duct and pancreatic duct, etc. If it invades the blood vessels around the bile duct, it can cause gastrointestinal bleeding, which can be manifested as vomiting blood. If pancreatic cancer is suspected or diagnosed, it is recommended to go to a regular hospital for a comprehensive assessment of the condition and follow the doctor’s instructions to avoid delaying the condition.