According to the world medical research, lung cancer is the cause of death for a significant portion of the diseases that take people’s lives. Thus, lung cancer has undoubtedly become the “cancer killer” that endangers human life and health. What are the symptoms and manifestations of lung cancer: Generally speaking, the early symptoms of lung cancer include cough, hemoptysis, chest pain, shortness of breath and other respiratory manifestations. However, it is clinically found that a considerable number of lung cancer patients do not show lung symptoms at the beginning but extra-pulmonary symptoms, which may cause misunderstanding and thus lose the time for early detection. Common extra-pulmonary manifestations of lung cancer include: manifestations related to abnormal secretion of substances by tumor cells: unexplained joint pain and finger pain in the extremities; pestle-like fingers (toes), i.e. distal end of fingers and toes in the shape of bulge; abnormal breast development in men; limb pain and weakness; swelling, hypertension and hyperglycemia; diarrhea, decreased food intake, emaciation and drowsiness; skin pigmentation and persistent rash, etc. Extra-pulmonary manifestations caused by lung cancer metastasis: such as headache, vomiting, hoarseness, low back pain, upper limb pain, etc., which are easily misdiagnosed as cerebrovascular accident, frozen shoulder, etc. In addition, lung cancer patients are often accompanied by headache symptoms in the process of lung cancer treatment: (1) Be alert to brain metastasis: the incidence of brain metastasis of lung cancer accounts for about 20% to 50%. If clinical symptoms such as headache, vomiting, twitching of limbs and mental abnormalities occur, brain CT should be done first to exclude brain metastasis. In addition, electroencephalogram and cerebral angiography are also helpful for diagnosis. (2) When lung cancer patients are under chemotherapy, some chemotherapeutic drugs such as vincristine, colchicine, fluorouracil, etc. have different degrees of damage to the central nervous system, which sometimes also cause headache. (3) When superior vena cava syndrome appears, it causes the occurrence of head and neck edema and headache due to the obstruction of blood return. (4) Patients with lung cancer often suffer from headache and dizziness due to poor gas exchange between the body and the outside world as a result of affected respiratory function, resulting in lower blood oxygen content and brain hypoxia. I hope that the above brief introduction about the early symptoms and treatment period of lung cancer can bring help to the patients, and I hope you can have more in-depth understanding and pay enough attention to lung cancer in the future, so that you can take good protective measures to stay away from lung cancer.