Non-small cell lung cancer antigen 3.34ng/ml is higher than normal, serious if caused by malignant tumors, not very serious if benign disease is treated in time. Cytokeratin 19 fragment, CYFRA21-1, is the preferred tumor marker for non-small cell lung cancer also known as non-small cell lung cancer antigen, with a normal value of 0~3.3ng/ml. Non-small cell lung cancer antigen 3.34ng/ml is slightly higher than the normal value range, may be caused by pneumonia, tuberculosis, mastitis and gynecological or urological, gastrointestinal and other benign diseases, generally timely treatment can be significantly improved. However, pneumonia and tuberculosis are also dangerous, such as severe pneumonia, which may be life-threatening. After the diagnosis is clear, full attention should be paid to it and treatment should be carried out as early as possible. Non-small cell lung cancer antigen 3.34ng/ml does not exclude the possibility of malignant tumors, and requires comprehensive assessment of the local lesions and general condition of the body after specific treatment. It is recommended that the patient should consult the doctor in time, analyze comprehensively with other existing examination data, identify the cause of the disease, and treat it actively.