Primary, or essential, high blood pressure is the most common type of high blood pressure. Most people who have high blood pressure have primary high blood pressure.¹

Many different factors can increase blood pressure, including obesity, resistance to insulin, high alcohol use, high salt intake, aging and perhaps sedentary lifestyle, stress, low potassium intake, and low calcium intake.

Other factors that may be involved in causing primary high blood pressure include:

• Changes in the complex system of hormones, brain chemicals, and nerves that normally help regulate blood pressure.
• Inherited (genetic) factors.

How blood pressure is determined

Blood pressure is determined by two factors:

• How much blood the heart pumps out in a given period of time (cardiac output)
• How difficult it is for blood to flow through the blood vessels (resistance)

An increase in one or both factors

An increase in one or both factors may cause blood pressure to rise. For example:

• If the body is not eliminating water or salt normally, extra water can build up in the bloodstream and in the body. The heart has to work harder to pump the larger volume of blood, which increases blood pressure.
• An imbalance in the systems that control the blood vessels can narrow the vessels, increase resistance, and raise blood pressure.