Lung nodule 20mm generally refers to the diameter of 20mm high-density shadow in the lung imaging examination, whether it is serious needs to be decided according to the nature of the patient’s nodule and the cause of the disease, etc. It is recommended to consult a doctor in a timely manner. If the nodule is caused by lung inflammation or tuberculosis, it can be cured by anti-infection or anti-tuberculosis medication, which is not considered serious. However, if the lung nodule 20mm is caused by benign or malignant tumors, you need to go to the hospital to do ct examination to further confirm the diagnosis, and after diagnosis, you need to carry out surgical treatment, and if necessary, carry out radiotherapy treatment, which is considered to be a serious situation. Lung nodules 20mm regardless of whether the condition is serious or not need to go to the hospital immediately for treatment, it is recommended that patients do not smoke and drink during the treatment period, to ensure adequate quality of sleep, the diet should be light, try not to take in spicy and stimulating food, so as not to aggravate the condition.