How to determine the cause of pain in half of the head needs to be judged according to the specific location, nature of the pain and the presence or absence of other accompanying symptoms. First, if the pain is intense, fluctuating, i.e., jumping pain, and recurrent. If the pain is severe, fluctuating, i.e., jumping pain, and recurring, with blurred vision, then it is very likely that the headache is a migraine. Secondly, if the pain on one half of the side is pinprick-like or lightning-like and stops suddenly, then it is more likely to belong to trigeminal neuralgia. Third, if the pain is vague and accompanied by nausea and vomiting, then the possibility of brain tumor cannot be excluded. So no matter which cause of headache, you should go to the neurology department of a regular hospital and let the doctor determine the specific cause based on the symptoms, signs and the results of brain CT, or brain MRI, for targeted treatment.