I will start from the beginning. Approx. 2 months ago, I have noticed I get a sharp headache behind my left ear down my neck. But, it only came when I started driving. Once I got out of my truck, the pain dissappeared. This has been happening quite frequently, almost every day. This week I bought a new car, jokingly wondering if my headache was due to my truck, which, BTW, was a new truck also,(1 year old). After the usual "car buying headache" went away, it was gone, or so I thought. I went to my Starbucks to have an afternoon Latte, and when I took my last sip, WHAM, it hit me down my neck again! Today I went out for Chinese, had the Green Tea, and I noticed I had the pain driving home tonight! Now, I do have 1 cup of Chai Tea every morning, and no headache from that. And I have been doing that for the past 2 years. Pills usually does not make it go away. What could it be?