Hepatocellular carcinoma, i.e. malignant tumor of the liver, can be divided into two categories: primary and secondary. Primary liver malignancies originate from the epithelial or mesenchymal tissues of the liver. The former is called primary liver cancer, which is a highly prevalent and dangerous malignancy in China; the latter is called sarcoma, which is less common compared with primary liver cancer. Secondary or metastatic hepatocellular carcinoma refers to the invasion of malignant tumors from multiple organs of the body to the liver. It is usually seen as liver metastasis from malignant tumors of stomach, biliary tract, pancreas, colorectum, ovary, uterus, lung, breast and other organs. The etiology and exact molecular mechanism of primary liver cancer are not fully understood. It is currently believed that its pathogenesis is a multifactorial and multi-step complex process, influenced by both environmental and consequent factors. Epidemiological and experimental research data indicate that hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, aflatoxin, drinking water contamination, alcohol, cirrhosis, sex hormones, nitrosamines, and trace elements are all associated with the development of liver cancer. Secondary hepatocellular carcinoma (metastatic hepatocellular carcinoma) can develop disease through different pathways, such as metastasis with blood or lymphatic fluid or direct invasion of the liver. Most patients with secondary liver cancer have tumor markers within the normal range, but a few metastatic liver cancers from the stomach, esophagus, pancreas and ovaries may have elevated AFP. Most symptomatic patients have elevated ALP and GGT. Elevated carcinoembryonic antigen CEA is helpful for the diagnosis of liver metastases, and the positive rate of CEA in colorectal cancer liver metastases is as high as 60%-70%. Selective hepatic angiography can detect lesions of 1 cm in diameter. Selective abdominal or hepatic artery angiography mostly shows less vascular tumors; CT shows mixed inhomogeneous isointense or hypointense occupancy, typically showing “bull’s eye” sign; MRI examination of liver metastases often shows uniform signal intensity, clear sides and multiple lesions, and a few have “target” sign or “bright ring”. “MRI often shows homogeneous signal intensity, clear edges and multiple lesions. Liver cancer symptoms: 1. Severe lack of appetite Liver cancer can cause pain and discomfort, emotional tension, lack of interest in food, and lack of mental and nutritional intake, which aggravate the condition of cancer patients. 2.Severe nausea and vomiting A common symptom of advanced cancer patients, which may be caused by the payment effect of treatment, or may be caused by cancer invasion of digestive or nervous system, and its symptoms are often more distressing than cancer pain. 3. Pain in liver area The normal tissues in advanced liver cancer will be damaged and infiltrated by the tumor, causing compression and destruction of adjacent nerve roots, local tissue ischemia and necrosis, obstruction of blood return, and infiltration of bone and periosteum can all cause pain. Therefore, pain is the most common complication of advanced liver cancer patients. 4.Malignant intracavitary effusion Malignant intracavitary effusion can occur in the thoracoabdominal cavity, peritoneal cavity and pericardial cavity in advanced liver cancer. 5.Respiratory distress is a difficult symptom for advanced cancer patients to deal with. Severe respiratory distress easily causes fear, and fear itself aggravates respiratory distress, which may cause death by shock if not treated timely. Hepatic coma is often a manifestation of the terminal stage of liver cancer. Gastrointestinal bleeding, secondary infection, large amount of diuretics and electrolyte disorders can often induce hepatic coma, so special attention should be paid in the late stage of liver cancer.