A headache when it is cold is usually a vascular headache. It is the most common type of headache and the most common type of primary headache. Its cause is not yet completely clear, but it is generally considered to be related to vasoconstriction and dilation dysfunction, and some people think that it is related to abnormal secretion of neurotransmitters in the brain, as well as trigeminal nerve vascular and regulatory dysfunction. It is often triggered by an obvious cause. Cold and cold wind are the most common causes, and patients are prone to it in winter when they do not wear hats or masks, ride bicycles or go out. There is also the tendency to occur in summer when blowing against electric fans, or against air conditioners. The location of the headache is relatively fixed, sometimes it is a one-sided headache, sometimes it is a bilateral temporal headache, and it is a paroxysmal swelling pain or throbbing pain.