The reasons why a bad night’s sleep can cause headaches are as follows: 1. Because the heart function is impaired. Because if a person does not sleep well, the heart function will not be able to operate normally, the contraction of the heart ejection function will be impaired, if the heart contraction ejection function is abnormal, it will lead to abnormal blood pressure, such as may cause a temporary increase in blood pressure, thus causing blood pressure fluctuations, changes in unstable blood pressure will have a pulling stimulating effect on the nerves in the brain, it will produce a headache this phenomenon. 2, if a person does not sleep well, it will The brain’s nerve function is abnormal, especially the function of the central nervous system. Because the function of the brain is extremely complex, it needs sufficient rest to be able to perform its function correctly, without good rest the function of the brain will be disrupted, especially the function of the cerebral cortex will be impaired, the brain cells will have some damage, these combined factors will appear bad sleep headache this phenomenon.