By 2004 this had increased to 29% and further to 32% (76 million US adults) by 2017. In 2017, with the change in definitions for hypertension, 46% of people in the United States are affected. African-American adults in the United States have among the highest rates of hypertension in the world at 44%. It is also more common in Filipino Americans and less common in US whites and Mexican Americans. Differences in hypertension rates are multifactorial and under study. Children
Rates of high blood pressure in children and adolescents have increased in the last 20 years in the United States. Childhood hypertension, particularly in pre-adolescents, is more often secondary to an underlying disorder than in adults. Kidney disease is the most common secondary cause of hypertension in children and adolescents. Nevertheless, primary or essential hypertension accounts for most cases. Prognosis
Hypertension is the most important preventable risk factor for premature death worldwide. It increases the risk of ischemic heart disease, strokes, peripheral vascular disease, and other cardiovascular diseases, including heart failure, aortic aneurysms, diffuse atherosclerosis, chronic kidney disease, atrial fibrillation, cancers, leukemia and pulmonary embolism. Hypertension is also a risk factor for cognitive impairment and dementia. Other complications include hypertensive retinopathy and hypertensive nephropathy. History
Measurement
Modern understanding of the cardiovascular system began with the work of physician William Harvey (1578–1657), who described the circulation of blood in his book "De motu cordis". The English clergyman Stephen Hales made the first published measurement of blood pressure in 1733.
Hypertension can also be caused by endocrine conditions, such as Cushings syndrome, hyperthyroidism, hypothyroidism, acromegaly, Conns syndrome or hyperaldosteronism, renal artery stenosis (from atherosclerosis or fibromuscular dysplasia), hyperparathyroidism, and pheochromocytoma. Other causes of secondary hypertension include obesity, sleep apnea, pregnancy, coarctation of the aorta, excessive eating of liquorice, excessive drinking of alcohol, certain prescription medicines, herbal remedies, and stimulants such as coffee, cocaine and methamphetamine. Arsenic exposure through drinking water has been shown to correlate with elevated blood pressure. Depression was also linked to hypertension. Loneliness is also a risk factor.A 2018 review found that any alcohol increased blood pressure in males while over one or two drinks increased the risk in females. Pathophysiology
In most people with established essential hypertension, increased resistance to blood flow (total peripheral resistance) accounts for the high pressure while cardiac output remains normal. There is evidence that some younger people with prehypertension or borderline hypertension have high cardiac output, an elevated heart rate and normal peripheral resistance, termed hyperkinetic borderline hypertension. These individuals develop the typical features of established essential hypertension in later life as their cardiac output falls and peripheral resistance rises with age. Whether this pattern is typical of all people who ultimately develop hypertension is disputed. The increased peripheral resistance in established hypertension is mainly attributable to structural narrowing of small arteries and arterioles, although a reduction in the number or density of capillaries may also contribute.It is not clear whether or not vasoconstriction of arteriolar blood vessels plays a role in hypertension.