^ Jump up to: a b c Giuseppe, Mancia; Fagard, R; Narkiewicz, K; Redon, J; Zanchetti, A; Bohm, M; Christiaens, T; Cifkova, R; De Backer, G; Dominiczak, A; Galderisi, M; Grobbee, DE; Jaarsma, T; Kirchhof, P; Kjeldsen, SE; Laurent, S; Manolis, AJ; Nilsson, PM; Ruilope, LM; Schmieder, RE; Sirnes, PA; Sleight, P; Viigimaa, M; Waeber, B; Zannad, F; Redon, J; Dominiczak, A; Narkiewicz, K; Nilsson, PM; et al. (July 2013). "2013 ESH/ESC Guidelines for the management of arterial hypertension: The Task Force for the management of arterial hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC)". European Heart Journal. 34 (28): 2159–219. doi:10.1093/eurheartj/eht151. PMID 23771844.
Your doctor may diagnose you with high blood pressure when you have consistent systolic readings of 140 mm Hg or higher or diastolic readings of 90 mm Hg or higher. Based on research, your doctor may also consider you to have high blood pressure if you are an adult or child age 13 or older who has consistent systolic readings of 130 to 139 mm Hg or diastolic readings of 80 to 89 mm Hg and you have other cardiovascular risk factors.
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 wasn’t long ago (2013) that those over 60 were advised to aim for blood pressure below 150/90. Now, as a result of a single large trial, the numbers are being revised in a major way. But as Dr. Gilbert Welch has pointed out at https://www.nytimes.com/2017/11/15/opinion/blood-pressure-guidelines.html , there are problems with this study. First, about 8% of patients aiming for 140 systolic (or less) had “cardiovascular events,” whereas only 6% of those in the 120 systolic group did. This is only a 2 point reduction, but as a percentage it’s a 25% reduction. This is the misleading use of percentage change instead of actual change. Second, the participants were already at higher than average risk for cardiovascular problems, so it was a study of a selected group and not of the general population.
Orthostatic hypotension symptoms: Going from a sitting or lying position to a standing position often brings out symptoms of low blood pressure. This occurs because standing causes blood to "settle" in the veins of the lower body, and this can lower the blood pressure. If the blood pressure is already low, standing can make the low pressure worse, to the point of causing symptoms. The development of lightheadedness, dizziness, or fainting upon standing caused by low blood pressure is called orthostatic hypotension. Normal individuals are able to compensate rapidly for the low pressure created by standing with the responses discussed previously and do not develop orthostatic hypotension.
Allergic reaction (anaphylaxis): Anaphylactic shock is a sometimes-fatal allergic reaction that can occur in people who are highly sensitive to drugs such as penicillin, to certain foods such as peanuts or to bee or wasp stings. This type of shock is characterized by breathing problems, hives, itching, a swollen throat and a sudden, dramatic fall in blood pressure.