Hello, Thank you for the query and welcome to healthcare magic. To give a definite answer I want to know more about your history like When did the symptoms start? Pattern of headache,frequency,quality of pain,any morning headache Any change in urinary symptoms like frequent urination associated with excessive thirst nausea,vomit History of similar symptoms in past Any change in menstrual cycles/heavy or decreased bleeding any medications used currently recent trauma , surgery Stress in life Dietary habits excessive thirst can be due to Diabetes Mellitus (Increased blood sugar) which I assume has already been looked for in your case and was normal Other possibility is Diabetes Insipidus which is due to decreased amount of a hormone resulting in excessive loss of water in urine. Diabetes Insipidus can result in headache due to dehydration, excessive thirst, tiredness etc You will need lab investigations like Anti diuretic hormone levels, Water restriction tests, blood electrolyte levels ,thyroid hormone levels More investigations may also be warranted depending on the history and initial results. I strongly recommend that you follow up with your doctor. Hope I answered your question please feel free to address any more concerns Regards, Dr.Lekshmi