Blood pressure is the build up of pressure in the arterio-vascular system over the normal amount of pressure that is needed for optimal cardiac functioning. The circulatory system is a closed system and in order for the heart to pump blood throughout the body a certain pressure is necessary. And, as the heart pumps, a surge of pressure in the arteries and veins is produced by the pumping action of the heart and this explains the difference between the bottom number (diastolic) and the top number (systolic) in the blood pressure reading.

What causes hypertension?

Medical science has not discovered a specific cause for high blood pressure. The majority of hypertension diagnoses are for the diagnosis of "Essential Hypertension" which means that there is no specific cause that can be blamed for the elevation in blood pressure.

To understand some potential causative factors and why many alternative treatment methods for hypertension are effective, it is useful consider the definition of high blood pressure given above; an increase of pressure in the circulatory system. You may or may not realize that the circulatory system is not like the plumbing in your house. The veins and arteries are not rigid but they expand and contract. They should expand and contract during normal functioning. Rigid and inflexible arteries (as in arterioscherosis, with a build up of placque and cholesterol) can be a causative factor in hypertension. But for those people who don't have "hardening of the arteries" there are other possible causes of increased tension in the circulatory system. Some examples are stress and fluid retention.

Anything that causes the blood vessels to narrow will cause a build up of pressure in the system circulatory system. Stress can cause the arteries to narrow as part of the natural "fight or flight" response. The muscles around the arteries tighten up under stress to help us survive the physical trauma of emergencies and function better when fighting or running away from a danger. Unfortunately our bodies sometimes lose the distinction between a physical threat where we must prepare for a physical attack and psychological threat and emotional upset. Our bodies will tighten up and our blood pressure will rise when we feel threatened by events in our lives. This is how biofeedback machines such as the Resperate, emWave PC, StressEraser, emWave Personal Stress Reliever, and GSR2/Temp work, they help you relax well which helps your blood vessels open up and expand which helps your body to lower it's blood pressure. The long term effect of feeling stressed and the body's habit of tightening up under the impact of stress can significantly contribute to hypertension so it stands to reason that reducing stress, reducing tightness of the body and the arteries will help to lower blood pressure.

Similarly, fluid retention in the body will increase the volume of blood in the circulatory system. This is why doctors recommend reduced sodium intake since sodium encourages water retention. Likewise, traditionally a diuretic is one of the first blood pressure medicines that a doctor would recommend to lower blood pressure. Reducing water retention reduces blood pressure.