“What are some unexpected sources of caffeine?”

I highly doubt if your high blood pressure is caused by caffeine, especially since you have eliminated all major sources of caffeine from your diet. The likelihood that you have significant levels of caffeine in your body is dubious and the test is probably wrong. You most likely have essential hypertension. That needs to be treated with antihypertensive medication. And the most common dietary influence on blood pressure is salt. You need to drastically reduce your salt intake, by avoiding all salty foods and not adding any salt to your diet. Obesity also contributes to hypertension. While large amounts of caffeine can raise your blood pressure, caffeine is a stimulant not unlike other stimulants which can also raise your blood pressure. Are you on any diet drugs like phentermine or decongestants (nasal or oral) such as phenylephrine, pseudoephedrine, or ADHD medications such as Ritalin or Adderall? Street drugs such as methamphetamine and cocaine can also severely raise blood pressure. There is a saying in medicine: "When you hear hoofbeats, don't think of zebras." Caffeine as the cause of your hypertension is probably a zebra-unlikely to be the cause.

William Z. Cohen, M.D., FAAFP

Please ask for a repeat test. Obviously a strict diet/food journal over a 2 week period will be helpful. If this all leads to your current starting point one should look elsewhere as the caffeine issue is probably less significant than initially thought.