Lung cancer patients with no sense of taste can be considered to be due to brain metastasis of lung cancer or oral mucositis of lung cancer patients. Lung cancer metastasis occurs in the brain through the bloodstream pathway, which causes nerve damage in the brain, and the nerves innervating the sense of taste in the brain are damaged, so the symptom of loss of sense of taste occurs, and it is usually necessary to do CT or MRI to find out the metastatic foci in the brain. There are also some lung cancer patients who suffer from severe mucositis in the oral cavity, which can also lead to loss of taste. The causes of mucositis include chemotherapy, radiotherapy, targeted drug therapy, etc. Generally speaking, the loss of taste caused by this kind of mucositis may still be recovered.