Dr. Greene's Answer
Blood pressure varies with the age of the child, and is closely related to height and weight. A one-year-old with a blood pressure of 110/70 has hypertension; a ten-year-old with 110/70 is normal.
One of the most common reasons for “high blood pressure” in children is a false reading obtained by using an inappropriately sized cuff. Children come in a wide variety of sizes; cuffs come in five: 3, 5, 7, 12, and 18 cm widths. (The lengths are not important as long as they fully encircle the arm.) The tables for normal blood pressures for children were compiled using cuffs of only these five widths, so while a reading obtained using the appropriate cuff may not reflect precisely the actual pressure in a child’s artery, it will tell you whether or not her blood pressure is in the normal range.
There are multiple varied recommendations for how to pick the appropriate blood pressure cuff size. Some experts recommend using the length of the upper arm to determine the cuff size. Others recommend using the circumference of the upper arm. (Pediatrics 1999;104;e30) While the exact calculations of size of cuff vary between these experts, all agree that a too-large cuff will underestimate blood pressure and a too-small cuff will overestimate blood pressure.
Whenever there is suspicion of cardiovascular disease in children, or if there is documented high blood pressure, blood pressure should be measured in both arms and in one leg. Underlying causes such as coarctation of the aorta (a congenital narrowing of the largest artery in the body) are often overlooked until a leg blood pressure is taken.
Your question is an excellent example of a much more far-reaching problem. In pediatrics we see people who vary as widely as a 2-pound premature infant differs from a 200-pound teenage linebacker. Children are not just little adults. Their development is complex. The disorders affecting growing humans are also complex — and often different from those affecting adults.
When children are examined and treated, they deserve equipment and personnel that are appropriate to them. Many clinics and emergency departments are not equipped with the proper sizes of tools. When children are sick and need to see a specialist, they are often taken to adult specialists who do not have either the tools or experience to optimally treat children. We would not think of sending an adult executive with a stroke to a pediatric neurologist, but children with seizures are often forced to see adults’ neurologists. Children are a large segment of our population; they represent our hope and our future. We must organize our healthcare delivery systems and health insurance protocols to insure the same quality of care we would give to an adult.