hi there, there are plenty of causes of headache as per literature and it wouldn't be appropriate to list all of them but yes the most common ones are caused due to refractive errors, tension headaches
, migrain. You need to first get a visit to the opthalmologist to be evaluated for refractive errors.Also get your blood pressure checked. Tension and lack of sleep are also aggravating factors and try to get enough sleep or rest. If your headache persists then visit your physician and let him evalute you for the same before initiating any treatment, Take care,.