The causes of cough and recurrent fever in patients are as follows: 1) respiratory tract infections, including bacterial infections, viral infections, and infections such as mycoplasma, chlamydia, and fungi; 2) abnormal regulation of the body temperature center, or abnormal heat dissipation from the skin; 3) absorption of fever from sterile necrotic material. For patients with cough and recurrent fever, imaging examination of the chest should be performed at this time, including chest X-ray or CT examination, in addition to checking whether some inflammatory indexes of the blood are elevated, including white blood cell count of routine blood, and C-reactive protein, calcitoninogen, etc. Patients with sputum should also undergo some pathogenic bacteria testing to clarify the nature of the specific pathogenic bacteria of the infection so that targeted treatment can be carried out.