Measuring blood pressure identifies how fast blood is moving through an individual's blood vessels. For adults, blood pressure typically is measured in millimeters of mercury (mmHg), and normal pressure typically hovers around 120/80 mmHg. In children, however, the pressure is measured against percentiles that correspond to the child's gender, height and age. Doctors use charts to determine percentiles. There is no set normal pediatric blood pressure range, but the general consensus is that a child is healthy if his results fall between the 50th and 90th percentiles
Blood pressure is measured by cutting off circulation to the blood vessels and listening to the sound that the blood makes as it moves throughout the body. Normal pediatric blood pressure in children differs according to gender and age. Additionally, blood pressure may also fluctuate depending on the height of the child. Unlike adult blood pressure, the blood pressure results of children are categorized according percentiles rather than specific numbers. When the number of the pediatric blood pressure is charted corresponding to the child's height and age, the percentile is obtained and used to assess the child's health.
Pediatric blood pressure is considered normal when the measurement falls below the 95th percentile, though results between the 90th and 95th percentile typically indicate a pre-hypertension stage. For instance, a three-year-old boy who falls in the 50th percentile based on the height chart and has a blood pressure measurement of 105/61 mmHg would have a blood pressure that falls into the 90th percentile, based on the pediatric blood pressure charts. In this case he might be diagnosed with pre-hypertension. If that same boy had a blood pressure reading of 91/46, his pressure would fall into the 50th percentile.
A normal blood pressure level can fluctuate significantly as the child grows in size and in age. For this reason, it is typically recommended that children receive two separate blood pressure tests during two visits to obtain an accurate reading. For kids who have already been diagnosed with high blood pressure, a normal pediatric blood pressure goal is either 130/80 mmHg or the 50th percentile, whichever is lower.
Although there is no set normal pediatric blood pressure range, the general consensus is that a child is healthy if the results fall between the 50th and 90th percentiles. Some physicians, however, may have general ranges they've developed through experience to determine healthy blood pressure levels. In children who are otherwise healthy, both the lowest blood pressure results and the highest numbers increase proportionally as the child ages and grows until he turns 17 years of age. Once a child turns 18, adult measurements should be used instead.