Whether the shadow of 5~7cm soft tissue mass in the left lung is serious should be judged according to the benign and malignant nature of the mass, benign mass is usually not serious, while malignant mass is more serious. 1. Benign masses: including fungal masses and malignant tumors, etc. Fungal infectious masses can be treated with sensitive antifungal drugs or surgery under the guidance of doctors, and the prognosis of patients is generally better through timely and effective treatment. As it may be difficult to differentiate from peripheral lung cancer, early surgical treatment can be performed, such as tumor removal, and the prognosis is generally better. 2. Malignant mass: usually lung cancer, patients often have symptoms such as cough, sputum, hemoptysis, chest pain, hoarseness, fever, emaciation, etc. Moreover, the cancer cells may metastasize to other parts of the body, such as kidney metastasis, bone metastasis, digestive tract metastasis, etc. Patients should undergo comprehensive treatment measures such as surgical treatment, radiotherapy, chemotherapy, targeted therapy, etc. as early as possible. It is suggested that patients should go to regular hospitals in time, complete relevant examinations, and follow the doctor’s instructions after clear diagnosis.