Hi welcome to HCM I can understand you concern for your constant headache Dear , inspite of all tests normal , there are many factors causing you the problem ,main are anxiety , sleeplessness , constipation , dehydration , indigestion- gas environmental triggers as hot or cold weather so on and so forth . Many of these factors can be taken care of by modifying your life style and food habits . Only medicines will not help cure Take balanced diet including all essential nutrients - minerals and Antioxidants . To detox the body , consume sufficient water and regular physical activity - walk- yoga ,pranayam - deep breathing , and proper sleep , meditation are all helpfull in maintaining trouble free life . Avoiding anxiety , sleeplessness , fried ,fast foods ,.tea coffee , alcohol smoking ,constipation and sadentry life style will help further . If problem persists ,consult your doctor . Hope this helps solve your query All the best .