Introduction Systemic hypertension remains one of the most common cardiovascular diseases in adults Over the past decade, several publications have highlighted the increasing prevalence of hypertension in children and young people and its increasing public health importance, mirroring the increasing prevalence of childhood obesity Moreover, it is increasingly also being recognized that childhood blood pressure levels track into adulthood, with abnormal blood pressure levels during childhood often resulting in hypertension as young adults There is an ongoing debate regarding the need for screening for elevated blood pressure in asymptomatic children as expert groups maintain that pediatric hypertension, overall, remains poorly recognized Primary or essential hypertension is the most common form of hypertension in adults, but it is becoming increasingly clear that the origin of this condition is in childhood and now accounts for the most common cause of hypertension in children 10 years or older The prevalence of primary hypertension during childhood is increasing, in keeping with the increasing prevalence of obesity Secondary hypertension is reported less frequently in older adolescents, although when present it results in more severe hypertension, often with more immediate clinical consequences, and is commonly caused by renal disease Early detection and control not only reduce the general morbidity of hypertension, but also protect the function of the already damaged kidney Fortunately, recent pharmacologic advances enable the blood pressure to be controlled in all patients, with minimal undesirable side effects Consequently, the management of hypertension is particularly rewarding for the practicing pediatrician Evaluation of Blood Pressure: Measurement, Normal Values, and Important Influences Measurement of Systemic Blood Pressure Measurement of blood pressure in children is usually first performed at the time of their first presentation to a pediatric department, or as part of their first school physical examination Unfortunately, it is often omitted Common reasons cited by clinicians include the practical difficulties in making measurements in infants and young children, changing normative limits throughout childhood, and the belief that hypertension is primarily an adult disease There are several aspects to measurement that need consideration These include the type of measuring machine, the type of cuff and bladder, the technique of measurement, and variables relating to the patient, the observer, and the environment in which the measurements are made Cuff and Bladder The cuff is the inelastic covering that encases an inflatable rubber bladder The cuff is usually made of cloth, using semisynthetic or any other material that will reliably and evenly transmit pressure over the artery once the bladder is inflated A combination that allows removal of the bladder from the cuff so that the cuff can be washed at regular intervals is probably more desirable.1 The inflatable bladder, rather than the cuff, needs to be of the correct size Failure to select the correct size of bladder remains the most common error in the measurement of blood pressure “Miscuffing” refers to the inaccuracy introduced as a result of using a bladder that is too small and narrow, or too long relative to the circumference of the upper arm It is advisable to choose a size of cuff in relation to the circumference of the arm as opposed to its length (Table 60.1) Although debated, most researchers in this area agree that the width for children should be about 40% of the circumference of the upper arm.2 This is because measurements made using circumference rather than length as the yardstick correlate best with intra-arterial readings In both adults and children, the use of cuffs that are too small in length, or too narrow in width, will overestimate the pressures measured by errors ranging from 3 over 2 to 12 over 8 mm Hg, with even greater ranges of error in obese individuals.3 This is sometimes referred to as cuff hypertension Too large a cuff is also recognized as a cause of underestimation of pressure in both adults and children.4–7 Length of the bladder is much more important in children than adults, and also leads to overestimation of the measured pressure.8 Table 60.1 Suggested Sizes of Suitable Sphygmomanometer Cuffs for Children Newborns Infants 1–5 years 6–9 years 10 years and over Obese adults Adult thigh Bladder Width (cm) 10 13 15 18 Bladder Length (cm) 5–10 12 15 20 23 30 36 Modified from Leuman EP Blood pressure and hypertension in childhood and adolescence In: Frick P, von Harneck GA, Martini GA, et al., eds, Advances in Internal Medicine and Pediatrics Berlin: Springer; 1979:109–183 The suggested solution to the problem of the size of the cuff is to have a range of sizes of bladder available In the United Kingdom, cuffs and bladders measuring 4 cm in width and 13 cm in length, and then 8 by 18 cm, 12 by 18 cm, 12 by 26 cm, and 12 by 40 cm, are available These usually suffice for arms of all sizes across the pediatric age range, including lean and obese children Other national societies recommend different sizes.5 The bladder should be centered over the brachial artery and should encircle from 80% to all of the upper arm.5,8 In practice, the widest cuff should be used to permit auscultation of the antecubital fossa Clinically, to reduce errors related to issues related to miscuffing, the authors suggest introducing recording of cuff size in patient case records so that sequential measurements can be compared in the same patient Instruments The mercury sphygmomanometer combined with an inflated cuff and auscultation remains the gold standard for the measurement of blood pressure in children Widely accepted percentiles for normal pressures through childhood have been developed using such a standard mercury sphygmomanometer ... Measurement of blood pressure in children is usually first performed at the time of their first presentation to a pediatric department, or as part of their first school physical examination Unfortunately, it is often omitted... Blood pressure and hypertension in childhood and adolescence In: Frick P, von Harneck GA, Martini GA, et al., eds, Advances in Internal Medicine and Pediatrics Berlin: Springer; 1979:109–183 The suggested solution to the problem of the size of the cuff is to have a range... 12 by 26 cm, and 12 by 40 cm, are available These usually suffice for arms of all sizes across the pediatric age range, including lean and obese children Other national societies recommend different sizes.5 The bladder should be centered