The causes of nausea and vomiting in advanced stage of liver cancer can be indigestion, ascites, affecting the function of gastrointestinal tract and other factors. 1. Dyspepsia: as liver cancer is malignant tumor of digestive system, with the expansion of cancer cells, normal digestive function of liver can be affected, which leads to nausea and vomiting, loss of appetite and other manifestations. 2. Ascites: as liver and albumin production are closely related, when liver function is damaged, it can lead to large amount of ascites, which can squeeze gastrointestinal organs and lead to abdominal distension, nausea and vomiting. 3. Impact on gastrointestinal function: on the one hand, when liver tumor is too big, it can cause certain pressure on gastrointestinal organs; on the other hand, when gastrointestinal metastasis occurs in advanced stage of liver cancer, it can lead to obstruction and inability to eat, which will lead to nausea and vomiting, etc. Patients need to consult hospitals in time. Patients need to go to the hospital in time to get a clear diagnosis and treatment plan, use drugs under the guidance of doctors and avoid self-medication.