Why Age-Specific Vital Signs Matter
Vital signs are the cornerstone of patient assessment, but a heart rate that is normal for an infant would indicate severe tachycardia in an adult, and a blood pressure normal for an adult would suggest hypertension in a child. Knowing age-specific normal ranges is essential for accurate assessment and appropriate clinical decision-making. The NREMT tests this knowledge frequently, and field practice demands it on every pediatric and geriatric call.
When interpreting vital signs, remember that "normal" ranges represent averages for a population. Individual patients may have baseline values outside these ranges. Trending vital signs over time is more valuable than any single measurement. A heart rate of 110 may be normal for an anxious patient, but if it was 80 ten minutes ago, that upward trend demands investigation.
Normal Vital Sign Ranges by Age
Neonates (Birth to 1 Month)
Heart rate: 120 to 160 beats per minute. Respiratory rate: 30 to 60 breaths per minute. Blood pressure: 60 to 80 systolic. Neonates have a limited ability to increase stroke volume, so they depend primarily on heart rate to maintain cardiac output. A heart rate below 100 in a neonate is concerning and below 60 requires CPR. Periodic breathing (brief pauses in respirations) is normal in neonates but apnea lasting more than 20 seconds is not.
Infants (1 Month to 1 Year)
Heart rate: 100 to 160 beats per minute. Respiratory rate: 25 to 50 breaths per minute. Blood pressure: 70 to 100 systolic. A useful formula for estimating minimum systolic blood pressure in infants and children is 70 + (2 times the age in years). Infants are obligate nose breathers until about 4 months of age, so nasal congestion alone can cause significant respiratory distress.
Children (1 to 10 Years)
Heart rate: 70 to 130 beats per minute (decreasing with age). Respiratory rate: 20 to 30 breaths per minute. Blood pressure: 80 to 110 systolic. Children have greater physiological reserve than adults and can compensate for significant blood loss or dehydration before showing signs of shock. When a child finally decompensates, they do so rapidly. A narrowing pulse pressure or decreasing mental status in a child should be treated as seriously as frank hypotension in an adult.
Adolescents and Adults
Heart rate: 60 to 100 beats per minute. Respiratory rate: 12 to 20 breaths per minute. Blood pressure: 90 to 140 systolic, 60 to 90 diastolic. Athletes may have resting heart rates as low as 40 to 50 due to increased cardiac efficiency. Consider the patient's baseline and any medications that might affect vital signs, such as beta-blockers that lower heart rate.
Geriatric Patients (Over 65)
Normal ranges are similar to adults, but interpretation requires more context. Many elderly patients have baseline hypertension, so a "normal" blood pressure of 120/80 could represent relative hypotension. Pulse oximetry readings may be less accurate due to poor peripheral circulation. Respiratory rates at the upper end of normal (18 to 20) may represent early distress because the elderly patient's reduced reserves prevent the dramatic tachypnea seen in younger patients.