heart association (aha) recommends at least three resting measurements on at least two separate health care visits. the uk national institute for health and care excellence recommends ambulatory blood pressure monitoring to confirm the diagnosis of hypertension if a clinic blood pressure is 140/90 mmhg or higher. measurement technique for an accurate diagnosis of hypertension to be made, it is essential for proper blood pressure measurement technique to be used. improper measurement of blood pressure is common and can change the blood pressure reading by up to 10 mmhg, which can lead to misdiagnosis and misclassification of hypertension. correct blood pressure measurement technique involves several steps. proper blood pressure measurement requires the person whose blood pressure is being measured to sit quietly for at least five minutes which is then followed by application of a properly fitted blood pressure cuff to a bare upper arm. the person should be seated with their back supported, feet flat on the floor, and with their legs uncrossed. the person whose blood pressure is being measured should avoid talking or moving during this process. the arm being measured should be supported on a flat surface at the level of the heart. blood pressure measurement should be done in a quiet room so the medical professional checking the blood pressure can hear the korotkoff sounds while listening to the brachial artery with a stethoscope for accurate blood pressure measurements. the blood pressure cuff should be deflated slowly (2–3 mmhg per second) while listening for the korotkoff sounds. the bladder should be emptied before a person's blood pressure is measured since this can increase blood pressure by up to 15/10 mmhg. multiple blood pressure readings (at least two) spaced 1–2 minutes apart should be obtained to ensure accuracy. ambulatory blood pressure monitoring over 12 to 24 hours is the most accurate method to confirm the diagnosis. an exception to this is those with very high blood pressure readings especially when there is poor organ function. with the availability of 24-hour ambulatory blood pressure monitors and home blood pressure machines, the importance of not wrongly diagnosing those who have white coat hypertension has led to a change in protocols. in the united kingdom, current best practice is to follow up a single raised clinic reading with ambulatory measurement, or less ideally with home blood pressure monitoring over the course of 7 days. the united states preventive services task force also recommends getting measurements outside of the healthcare environment. pseudohypertension in the elderly or noncompressibility artery syndrome may also require consideration. this condition is believed to be due to calcification of the arteries resulting in abnormally high blood pressure readings with a blood pressure cuff while intra arterial measurements of blood pressure are normal. orthostatic hypertension is when blood pressure increases upon standing. other investigations typical tests performed system tests kidney microscopic urinalysis, protein in the urine, bun, creatinine endocrine serum sodium, potassium, calcium, tsh metabolic fasting blood glucose, hdl, ldl, total cholesterol, triglycerides other hematocrit, electrocardiogram, chest radiograph once the diagnosis of hypertension has been made, healthcare providers should attempt to identify the underlying cause based on risk factors and other symptoms, if present. secondary hypertension is more common in preadolescent children, with most cases caused by kidney disease. primary or essential hypertension is more common in adolescents and adults and has multiple risk factors, including obesity and a family history of hypertension. laboratory tests can also be performed to identify possible causes of secondary hypertension, and to determine whether hypertension has caused damage to the heart, eyes, and kidneys. additional tests for diabetes and high cholesterol levels are usually performed because these conditions are additional risk factors for the development of heart disease and may require treatment. initial assessment of the hypertensive people should include a complete history and physical examination. serum creatinine is measured to assess for the presence of kidney disease, which can be either the cause or the result of hypertension. serum creatinine alone may overestimate glomerular filtration rate and the 2003 jnc7 guidelines advocate the use of predictive equations such as the modification of diet in renal disease (mdrd) formula to estimate glomerular filtration rate (egfr). egfr can also provide a baseline measurement of kidney function that can be used to monitor for side effects of certain anti-hypertensive drugs on kidney function. additionally, testing of urine samples for protein is used as a secondary indicator of kidney disease. electrocardiogram (ekg/ecg) testing is done to check for evidence that the heart is under strain from high blood pressure. it may also show whether there is thickening of the heart muscle (left ventricular hypertrophy) or whether the heart has experienced a prior minor disturbance such as a silent heart attack. a chest x-ray or an echocardiogram may also be performed to look for signs of heart enlargement or damage to the heart. classification in adults classification in adults (persons with systolic and diastolic in different categories are assigned to the higher category.) category systolic, mmhg diastolic, mmhg hypotension < 90 < 60 normal 90–11990–129 60–7960–84 prehypertension(high normal, elevated) 120–129130–139 60–7985–89 stage 1 hypertension 130–139140–159 80–89 90–99 stage 2 hypertension >140160–179 >90100–109 hypertensive crises ≥ 180 ≥ 120 isolated systolic hypertension ≥ 140 < 90 isolated diastolic hypertension < 140 ≥ 90 diastolic vs systolic blood pressure chart comparing european society of cardiology and european society of hypertension classification with reference ranges in children in people aged 18 years or older, hypertension is defined as either a systolic or a diastolic blood pressure measurement consistently higher than an accepted normal value (this is above 129 or 139 mmhg systolic, 89 mmhg diastolic depending on the guideline). other thresholds are used (135 mmhg systolic or 85 mmhg diastolic) if measurements are derived from 24-hour ambulatory or home monitoring. international hypertension guidelines have also created categories below the hypertensive range to indicate a continuum of risk with higher blood pressures in the normal range. the seventh report of the joint national committee on prevention, detection, evaluation and treatment of high blood pressure (jnc7) published in 2003 uses the term prehypertension for blood pressure in the range 120–139 mmhg systolic or 80–89 mmhg diastolic, while european society of hypertension guidelines (2007) and british hypertension society (bhs) iv (2004) use optimal, normal and high normal categories to subdivide pressures below 140 mmhg systolic and 90 mmhg diastolic. hypertension is also sub-classified: jnc7 distinguishes hypertension stage i, hypertension stage ii, and isolated systolic hypertension. isolated systolic hypertension refers to elevated systolic pressure with normal diastolic pressure and is common in the elderly. the esh-esc guidelines (2007) and bhs iv (2004) additionally define a third stage (stage iii hypertension) for people with systolic blood pressure exceeding 179 mmhg or a diastolic pressure over 109 mmhg. hypertension is classified as "resistant" if medications do not reduce blood pressure to normal levels. in november 2017, the american heart association and american college of cardiology published a joint guideline which updates the recommendations of the jnc7 report. the 2020 international society of hypertension guidelines define hypertension based on office blood pressure ≥140/90 mmhg or home monitoring blood pressure ≥135/85 mmhg, or 24-hour ambulatory blood pressure average ≥130/80 mmhg (daytime average ≥135/85 mmhg or nighttime average bp ≥120/70 mmhg). children hypertension occurs in around 0.2 to 3% of newborns; however, blood pressure is not measured routinely in healthy newborns. hypertension is more common in high risk newborns. a variety of factors, such as gestational age, postconceptional age and birth weight needs to be taken into account when deciding if a blood pressure is normal in a newborn. hypertension defined as elevated blood pressure over several visits affects 1% to 5% of children and adolescents and is associated with long-term risks of ill-health. blood pressure rises with age in childhood and, in children, hypertension is defined as an average systolic or diastolic blood pressure on three or more occasions equal or higher than the 95th percentile appropriate for the sex, age and height of the child. high blood pressure must be confirmed on repeated visits however before characterizing a child as having hypertension. prehypertension in children has been defined as average systolic or diastolic blood pressure that is greater than or equal to the 90th percentile, but less than the 95th percentile. in adolescents, it has been proposed that hypertension and pre-hypertension are diagnosed and classified using the same criteria as in adults. prevention much of the disease burden of high blood pressure is experienced by people who are not labeled as hypertensive. consequently, population strategies are required to reduce the consequences of high blood pressure and reduce the need for antihypertensive medications. lifestyle changes are recommended to lower blood pressure, before starting medications. the 2004 british hypertension society guidelines proposed lifestyle changes consistent with those outlined by the us national high bp education program in 2002 for the primary prevention of hypertension: maintain normal body weight for adults (e.g. body mass index 20–25 kg/m2) reduce dietary sodium intake to <100 mmol/ day (<6 g of sodium chloride or <2.4 g of sodium per day) engage in regular aerobic physical activity such as brisk walking (≥30 min per day, most days of the week) limit alcohol consumption to no more than 3 units/day in men and no more than 2 units/day in women consume a diet rich in fruit and vegetables (e.g. at least five portions per day); stress reduction avoiding or learning to manage stress can help a person control blood pressure. a few relaxation techniques that can help relieve stress are: meditation warm baths yoga going on long walks effective lifestyle modification may lower blood pressure as much as an individual antihypertensive medication. combinations of two or more lifestyle modifications can achieve even better results. there is considerable evidence that reducing dietary salt intake lowers blood pressure, but whether this translates into a reduction in mortality and cardiovascular disease remains uncertain. estimated sodium intake ≥6g/day and <3g/day are both associated with high risk of death or major cardiovascular disease, but the association between high sodium intake and adverse outcomes is only observed in people with hypertension. consequently, in the absence of results from randomized controlled trials, the wisdom of reducing levels of dietary salt intake below 3g/day has been questioned. esc guidelines mention periodontitis is associated with poor cardiovascular health status. the value of routine screening for hypertension is debated. in 2004, the national high blood pressure education program recommended that children aged 3 years and older have blood pressure measurement at least once at every health care visit and the national heart, lung, and blood institute and american academy of pediatrics made a similar recommendation. however, the american academy of family physicians supports the view of the u.s. preventive services task force that the available evidence is insufficient to determine the balance of benefits and harms of screening for hypertension in children and adolescents who do not have symptoms. the us preventive services task force recommends screening adults 18 years or older for hypertension with office blood pressure measurement. management main article: management of hypertension according to one review published in 2003, reduction of the blood pressure by 5 mmhg can decrease the risk of stroke by 34%, of ischemic heart disease by 21%, and reduce the likelihood of dementia, heart failure, and mortality from cardiovascular disease. target blood pressure