It is still common to have a bad cough after chemotherapy, because chemotherapy is more damaging to the body’s white blood cells, the body’s immunity will drop sharply, and at this time, once the slightest viral or bacterial infection, it is easy to cause lung infection and possibly pneumonia. The first thing to do is to go for a chest CT. If pneumonia does occur, it must be treated with an antibiotic infusion, and you need to go for routine blood tests and C-reactive protein first, and if there is an elevation in C-reactive protein, it means it is caused by inflammation. It is best to do sputum culture and drug sensitivity test, and according to the results of sputum culture and drug sensitivity test, choose sensitive antibiotics for treatment. If the cough is severe due to a viral infection, you can use antiviral drugs such as Xiyampin or Ribavirin at the same time. If there are positive antibodies to mycoplasma, it is a bad cough caused by mycoplasma infection, and you need to use anti-mycoplasma drugs, such as macrolide antibiotics, such as azithromycin and roxithromycin, which are more effective. If you have a bad cough, you also need to use cough and phlegm relieving drugs, such as compound licorice combination.