The flowering plant in the daisy family known as Feverfew has been promoted for treating headaches, fevers and arthritis. It is a very popular supplement when it comes to treating migraines. A study has shown that Feverfew has pain killing and anti-inflammatory properties which help to reduce the production of histamine in the brain. An overabundance of histamine in the brain may cause anxiety, high blood pressure, tissue swelling, difficulty regulating blood temperature, abdominal cramps, dizziness and irregular heart rate.