Whether a lung nodule of 0.8 cm is serious or not is mainly related to the nature of the lung nodule. Benign nodules are generally not serious and malignant lung nodules have serious consequences. 1. Benign lung nodules: 0.8cm lung nodules for benign lung nodules is more likely, this situation is generally not serious, such as patients without clinical symptoms, can not be dealt with, regular observation can be, such as the presence of pain, chest tightness and other discomforts, can be surgical resection. 2. Malignant lung nodule: 0.8cm lung nodule is less likely to be malignant, but it cannot be excluded. If the patient’s nodule is malignant, the situation is more serious, and it must be treated with surgery, and postoperative radiotherapy is needed to completely eradicate the cancerous cells if necessary. Whether a lung nodule of 0.8 cm is serious or not requires further examination by the patient to clarify the nature of the nodule and then make a judgment.