Patients should sit quietly in a backed chair for a minimum of 5 minutes (not at the consultation table) with sleeves removed and upper arms positioned at the level of the heart. No smoking or caffeine-containing food 30 minutes prior to the measurement. Each patient should be informed verbally and in writing of the specific blood pressure value and the blood pressure target value. Proper blood pressure measurement requires a cuff that fits the size of the upper arm. Right-arm measurements are highly consistent and comparable to standard forms. The appropriate cuff size is determined by having a cuff width of approximately 40% of the circumference of the upper arm measured through the ulnar eminence and the midpoint of the acromion. The issue of cuff size is particularly important in children (see guideline 13) and in obese adults, many of whom require larger cuffs as the prevalence of obesity increases. For those with a tapered upper arm and a circumference >41 cm blood pressure should be taken on the forearm. Too small a cuff can lead to false over-readings of 3.2/3.4 to 12/8 mmHg, and up to 30 mmHg in obese individuals. too large a cuff will lead to false under-readings of 10 to 30 mmHg. The cuff should be inflated around at least 80% of the arm circumference. The stethoscope chest piece should be placed lightly above the proximal to mid-brachial pulsation of the ulnar fossa, below the bottom edge of the cuff (i.e., 2 cm above the ulnar fossa). The cuff should be inflated to a perceptible SBP (systolic blood pressure (30 mmHg or more, deflated at a rate of 2 to 3 mmHg/sec. Both systolic and diastolic blood pressures should be recorded. The blood pressure at which the sound is first heard (first period) is the systolic blood pressure, and the sound disappears (fifth period) is the adult diastolic blood pressure. It is recommended to record in detail the blood pressure at the initial visit, the position, the arm chosen, the method of blood pressure measurement used, the blood pressure of both upper extremities, the circumference of the upper extremities and the cuff used, the blood pressure of the fourth and fifth period of the auscultation method (Korotkoff method) (representing the difference in auscultation), the emotional state of the patient and the time of medication administration. Readings from 2 or more measurements taken 2 minutes apart should be taken as an average. If the difference between the first two readings is greater than 5 mmHg, the readings should be taken again and averaged. If the blood pressure is elevated it must be measured again at another appointment to confirm the diagnosis of hypertension. High levels of blood pressure will decrease with subsequent measurements because of: 1) an adaptive adjustment effect (i.e., less anxiety to see the doctor again); and 2) regression to the mean, an abiotic phenomenon derived in part from mathematical factors. Blood pressure levels are not stable and unchanging, and can vary in a standard resting state. A more accurate blood pressure level for a person is the average of several repeated measurements over a period of weeks to months. Especially in the elderly and children, systolic blood pressure is a better predictor of end-organ damage events (coronary heart disease, CVD, heart failure, stroke, kidney failure, and all-cause mortality) than diastolic blood pressure. In recent years it has become clear that elevated pulse pressure difference (systolic minus diastolic, representing the vascular compliance of the great vessels) is a better predictor of increased cardiovascular risk than SBP or DBP alone. Novel noninvasive techniques that can measure vascular compliance are being validated, and early evidence suggests that patients with CKD have reduced vascular compliance. In specific cases, supine, sitting and standard postures (standing quietly for 2-5 minutes) can suggest and help diagnose autonomic dysregulation. Standing SBP changes >10 mmHg with vertigo or pallor are common in elderly patients with systolic hypertension, diabetes mellitus, use of diuretics, vasodilators (nitrates, alpha antagonists and sildenafil-like drugs) and certain psychotropic drugs. The same can be said for patients whose blood pressure changes too drastically with body position after taking medications (peripheral adrenergic receptor blockers, alpha receptor antagonists, high-dose diuretics). In these cases it is appropriate to measure ABMP (automatic blood pressure monitoring). Blood pressure measurement in the elderly requires special attention. When measuring blood pressure according to the pulse beat, some elderly people have pseudohypertension (pseudohypertensive meter readings) due to vascular stiffness. Also, elderly patients with hypertension, especially women, may have white coat hypertension and excessive fluctuations in systolic blood pressure. In the absence of target organ damage, physicians should consider pseudohypertension or white coat hypertension. ABPM is useful in such cases. The preferred sphygmomanometer is the mercury sphygmomanometer. Proven electronic instruments and calibrated fluid-free sphygmomanometers may also be used.