Patients who experience headaches when inhaling secondhand smoke excessively are mainly considered to be related to vascular neurological headache, cerebrovascular disease, migraine, and other causes. Usually patients inhaling secondhand smoke is equivalent to passive smoking, and headache symptoms can be relieved within a few hours after promptly leaving the passive smoking environment and going out to breathe fresh air: 1, vascular neurological headache: such patients may suffer from excessive inhalation of harmful substances such as cigarette tar, nicotine and carbon monoxide, which may cause insufficient oxygen supply to the brain, and then cause transient cerebral ischemic attacks, thus manifesting as headache; 2 If the patient has cerebrovascular disease, such as cerebral atherosclerosis, excessive inhalation of secondhand smoke can lead to platelet aggregation, causing impaired blood flow resistance; secondly, if the patient has pathological changes such as cerebral atherosclerosis, it can cause the patient to have insufficient blood supply to the brain, which can lead to headache; 3. Migraine: patients with long-term migraine can also have headache symptoms after excessive inhalation of secondhand smoke. Because the nicotine in cigarettes can stimulate the brain nerves by olfaction, promote the release of substance P, calcitonin gene-related peptide and other neuropeptides, and act on the patient’s cerebral blood vessels to cause vasodilation, and then headache. Therefore, the above-mentioned patients should stay away from the smoking population and exercise properly to enhance their physical fitness, while patients with chronic severe headaches should seek medical attention for further diagnosis.