Low-density shadow in the left lobe of the liver does not matter if it is a benign lesion, but malignant lesions are more serious. 1. Low-density shadow in the left lobe of the liver may be benign lesions, such as fatty liver, hepatic hemangioma, hepatic cyst, hepatic nodular hyperplasia, etc. These are all benign lesions, which are not serious, and most of the patients can be cured through timely treatment and will not be left with sequelae. However, if treatment is neglected, it may cause various discomforts. 2. Low-density shadow in the left lobe of the liver may also be malignant lesions, such as primary hepatocellular carcinoma and secondary hepatocellular carcinoma. The disease is more serious, but early regular treatment can effectively prolong the survival period and improve the quality of life of patients; when it develops into middle or late stage, the condition is more complicated and may threaten the life of patients at any time. At present, low density in the left lobe of the liver is detected, and it is recommended to further do enhanced CT, magnetic resonance, and tumor marker screening to analyze the cause, and then according to the doctor’s guidance for targeted treatment.