The etiology of hypertension is the study of the origins of high blood pressure. It can also refer to the cause or causes of hypertension in a population generally, or a specific individual's etiology of hypertension. The great majority of hypertension cases have no single identifiable cause, but many contributing factors have been identified. Family history accounts for perhaps a quarter of the risk of hypertension, and other genetic considerations exist. Other contributing factors include dietary, behavioral, and lifestyle choices or patterns.
It is usually estimated that up to 95% of people diagnosed with hypertension have what is called primary or essential hypertension. In medicine, primary means that a condition has no apparent underlying cause. Essential and idiopathic are synonyms for primary. Thus, most populations and people do not have an identifiable etiology of hypertension. There are a number of causes of secondary hypertension, for which an underlying cause can be determined. Secondary hypertension causes include disorders of the kidneys or the nearby adrenal glands, among others.
There are a number of factors that contribute to primary hypertension; some can be changed or modified, and others cannot. Genetic factors that can't be changed include race, gender, and family history. The risk of developing hypertension is higher when parents or siblings have diagnosed hypertension, sometimes estimated to be 25% greater. Blacks on the whole tend to have higher blood pressure than whites, putting them at greater risk of hypertension. Men have a greater risk than women before age 50, but women have higher blood pressure after that age.
By definition, there is a specific etiology of hypertension when it is diagnosed as secondary hypertension. Renovascular hypertension is caused by a narrowing of the arteries that supply the kidneys with blood, a condition that is usually treatable. Disorders of the adrenal glands, which help regulate blood pressure, can cause hypertension. Thyroid conditions can also cause high blood pressure. A rare and often benign tumor known as a pheochromoctyoma can also contribute to high blood pressure.
Many factors involved in the etiology of hypertension can be changed through lifestyle modifications. Cigarette smoking raises blood pressure for about thirty minutes, so chronic smokers are likely to have elevated blood pressure throughout the day. Consuming alcohol above a drink or two raises blood pressure as long as alcohol is in the body. Obesity is linked with high pressure, as is excessive stress. Regular exercise can help to reduce both.
Study of the etiology of hypertension has resulted in certain dietary recommendations. Although about half of the people diagnosed with hypertension are sensitive to dietary sodium, reducing excessive sodium intake is recommended for most people. Ensuring adequate potassium intake by eating plenty of fruits and vegetables reduces hypertension risk in a measurable way.
