Avoid coffee 24-48 hrs before your medical as it may increase your BP. Diet and exercise with weight in check as a long term solution. There are several yoga type(search you tube) breathing exercises you can do that seem to work. When you get to the facility try to have 5-10 minutes of quiet time before the reading is taken. If all else fails and you need medication then the FAA is pretty good about certifying you while on it without much fuss. Bottom line, even a 5-10 lb weight loss (if overweight) can make all the difference. Oh, also hydrate.