A cough that lasts more than two weeks needs to be taken seriously. It is best to go to the hospital for routine blood tests, C-reactive protein, antibodies to Mycoplasma pneumoniae, and chest x-rays or CT examinations to clarify the cause before treating it with the right medication. Common diseases include acute bronchitis and lung infections, and coughs caused by mycoplasma can have a longer course. In the case of mycoplasma bronchitis or pneumonia, the cough is mostly dry with little or no sputum, and the routine blood leukocytes are usually normal. Azithromycin is more effective for mycoplasma infections. In the case of pneumonia, most of the patients had fever or still have recurrent fever, it is best to choose antibiotics to fight the infection according to the results of sputum culture allergy, together with the use of phlegm-suppressing and asthma-calming drugs.