The causes of headache when coughing are as follows: 1. Changes in pressure in the chest and abdomen when coughing lead to rapid changes in blood supply to the head, resulting in headache; 2. Peripheral inflammation caused by viral infection, as well as vasodilatation and pulling stimulation of vascular sensory endings, thus causing lesions in the extra-neural plexus, can trigger headache; 3. Upper respiratory tract infection: rhinitis and paranasal sinusitis can lead to rhinogenic headache; 4. Intracranial hypertension: if a patient has severe headache with vomiting and cervical tonicity, the possibility of intracranial hypertension should be considered.