Hello Chronic headaches can be a result of certain conditions like tension headache,migraine headache, and cluster headache.A CT Scan is been done to rule out any major problems like a brain tumour or mass.As you mentioned that two CT Scans were done,what was the duration between each?Also what were the areas covered?Example Brain,Sinuses,Orbits,Cervical Spine,etc Few possibilities like poor posture, emotional stress,fatigue or overexertion can cause tension headaches and could be the reason for the headache.More women suffer from Tension headaches than males. Pain Relievers and Anti depressants may be prescribed under the supervision of a physician.So do follow up with a physician. If this answers your querry,do close the discussion by rating the answer.Or else do please reply back.Thanks