
Green tea helps ease painful headaches because of its caffeine content, which helps open up the constricted blood vessels that are causing the pain. However, consuming caffeine is a balancing act, since everyone has a different tolerance, and too much of it can actually cause a headache. The best thing to do is to test your tolerance for caffeine by starting out with one small cup of tea when you get headache. Drink the green tea as soon as you notice you are experiencing headache symptoms, because often times your headache can be totally staved off if it is caught early.
However, if your headache was brought on by consuming too much caffeine, do not use green tea to relieve it. Increasing your caffeine intake can make the headache even worse. Drinking water to flush the caffeine out of your system is the best thing to do in this case, and often those headaches are caused by dehydration.