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Dr. Alessandro Giardini
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Blood pressure rises throughout childhood. A systolic reading of 85 mmHg at age one is entirely normal in a boy; the same figure at seventeen would prompt investigation. Age-specific reference tables are the only reliable guide.
Many parents arrive in clinic having already searched their child's reading online and compared it against adult thresholds. That comparison rarely helps. The adult cut-off of 120/80 mmHg applies to adults only, and using it for children creates confusion in both directions: flagging readings that are perfectly appropriate for a ten-year-old, and occasionally failing to raise concern when concern is warranted. Getting the reference wrong matters. Normal blood pressure in children shifts with age, sex, and height. A table calibrated for adults will not serve a child well.
In my practice blood pressure monitoring features in almost every consultation I conduct. Children with hypertrophic cardiomyopathy, Marfan syndrome, or a family history of early cardiovascular disease need systematic surveillance. Adolescents on stimulant medication for ADHD, or those presenting with PoTS, require careful attention to blood pressure trends. Accurate interpretation depends on the right age-appropriate reference, and that reference needs to be accessible to parents as well as clinicians. The table below provides exactly that.
Every reading deserves an appropriate comparison. Please find a complete guide on high blood pressure in children here.
Normal blood pressure in children depends on age, sex, and height. A one-year-old boy with a systolic reading of 85 mmHg is entirely within the normal range; that same figure in a seventeen-year-old would be considered low. The table on this page provides age-specific and sex-specific reference values at the 50th height percentile, based on the NHLBI Fourth Report and AAP guidelines, and is the most practical starting point for any parental concern about a reading.
Blood pressure is considered elevated when the systolic or diastolic reading consistently falls at or above the 90th percentile for the child's age, sex, and height. Readings at or above the 95th percentile on at least three separate occasions meet the diagnostic threshold for stage 1 hypertension in children. A single high reading, particularly if the child was anxious, distressed, or in pain at the time of measurement, is not sufficient for a diagnosis.
Yes. Blood pressure reference values differ between boys and girls throughout childhood and adolescence. Boys tend to have slightly higher systolic values from around mid-childhood onwards, and the divergence becomes more marked during adolescence. The table on this page provides separate reference columns for boys and girls, reflecting the sex-specific normative data from the NHLBI Fourth Report on which paediatric guidelines are based.
The adult cut-off of 120/80 mmHg was established from population studies in adults and does not reflect the physiological normal range in a growing child. Applying it to a child would flag many perfectly normal readings as elevated and, in some age groups, fail to identify readings that genuinely warrant attention. Paediatric blood pressure thresholds are derived from large normative datasets in children and vary with age, sex, and height precisely because the cardiovascular system is still developing.
A reading at the 90th percentile sits at the upper edge of the normal range and is classified as elevated under current paediatric guidelines. It does not indicate established hypertension, but it warrants repeat measurement on at least two further occasions, attention to contributing factors such as weight and dietary salt intake, and monitoring over time. A specialist opinion is appropriate if readings remain consistently at this level across multiple separate visits.
A paediatric cardiology assessment is appropriate if your child's blood pressure consistently exceeds the 90th percentile for their age and sex on more than one occasion, if a GP or school nurse has raised a concern, or if your child has a known heart condition, kidney disease, or a family history of early hypertension. Children with hypertrophic cardiomyopathy, Marfan syndrome, aortic coarctation, or Loeys-Dietz syndrome all require particularly careful blood pressure monitoring as part of their routine cardiac review.
Author: Dr. Alessandro Giardini, MD, PhD
Written 12/05/2026