Primary Blood Pressure
The cause of primary high blood pressure is unknown. It appears to simply develop gradually on its own over time. The underlying cause of up to 95 percent [3] of high blood pressure cases in the United States cannot be found. While the cause is unknown, some risk factors have been identified.
Genes
High blood pressure tends to run in families. People whose parents have high blood pressure are at a greater risk of developing it. The risk is higher if both parents have high blood pressure. The details of how and why this happens are not known to scientists yet.
The role genes play in causing high blood pressure is complex. Some scientists believe that there isn’t one single gene responsible for the condition. Instead, multiple genes [4], through subtle changes in response to various stimuli, contribute to the development of this problem.
Over 100 genetic variations [5] have been linked to primary hypertension. Changes in the genes that control the renin-angiotensin-aldosterone system are suspected to play a major role. This is because the renin-angiotensin-aldosterone system produces hormones that regulate blood pressure and fluid and salt balance in the body. Genes involved with blood vessel lining may also contribute to high blood pressure. Variations in how these genes work may cause the blood vessels to constrict or narrow, resulting in elevated blood pressure. There are many more genes that likely contribute to hypertension; their precise roles are yet to be known.