A headache when blowing air conditioning may be caused by the air conditioning temperature is too low, blood vessel contraction, may also be the symptomatic manifestation of certain diseases, such as cervical spondylosis, colds, cerebrovascular disease, etc., and should be promptly consulted to find out the cause of the disease. 1. Vasoconstriction: If the air conditioning temperature is too low, prolonged cold air stimulation can cause vasoconstriction throughout the body, small blood vessel contraction of the brain blood circulation and supply can cause certain effects, thus appearing in the air conditioning headache. 2. Cervical cervical spondylosis: when blowing the air conditioner, the neck and shoulders are easily stimulated by the cold, neck pain, back muscle stiffness and other manifestations of this pain involved in the occipital cervical fascia pain, can be along the occipital side of the back of the head radiated to the front. 3. Cold: blowing the air conditioning temperature is too low, can make people have a cold, which induces headache, but also nasal congestion, sneezing, sore throat, fever and other symptoms. 4. Cerebrovascular disease: cerebral hemorrhage and other patients suffering from cerebrovascular disease can also appear a blowing air-conditioning headache, may be due to the cerebral blood vessels by the cold stimulation of cerebral vasoconstriction caused by spasm. And a long time open air conditioning will lead to indoor air circulation, the oxygen concentration in the air is reduced, causing brain tissue hypoxia ischemia, so there will be dizziness, headache symptoms. If you have a headache as soon as you blow the air conditioner, it is recommended that the patient consult a doctor in a timely manner to improve the relevant examination to clarify the cause of the disease. At the same time, daily outdoor activities should be increased to avoid prolonged air-conditioning.