Pain syndrome and how pain presents in body and how it effect life it is so complicated patient tolerance to pain is different and dealing with pain for different people is different as well. Responding to pain medication is different to people as well also approaching to pain and evaluating the pain is different and also doctors deal with pain differently. When pain exists is it s not normal it I snot a normal physiology it is a pathology and just giving pain killer it is symptomatology relief but if pathology exists pain will return soon or later so the best way is while treating the pain as a symptoms need to evaluate the patient to see where the pain comes from I can give some examples where the pain comes from. tension headaches, sinus pressure headaches, migraine, cluster headache, intra cranial pathology, seizures, infections, inflammations, and so on. Pain evaluation is a combination initial evaluation/ assessment with review of systems, physical exam, and possibly ordering laboratories and some imaging studies to get some preliminary data and sometimes for example doing deeper studies such as EEG ( electroencephalogram ) to rule out causes like seizure or seizure like activities in bran that may presents with headache.