Vital signs by age: normal ranges for nurses

Normal vital signs change significantly across the lifespan. A heart rate of 140 bpm is perfectly expected in a neonate and a serious tachycardia in an adult. A blood pressure of 90/60 mmHg is concerning in an older adult and within normal limits in a toddler. Applying adult values to children — or failing to account for how aging shifts baselines — is one of the most common clinical errors nursing students make. This reference covers normal ranges for heart rate, respiratory rate, blood pressure, temperature, and oxygen saturation for every major age group, from neonates through older adults, with clinical notes on why the numbers differ and when to escalate.

Quick reference table: normal vital signs by age

Sources: PALS (Pediatric Advanced Life Support) guidelines; AAP clinical practice parameters; ACC/AHA 2017 Hypertension Guideline; Potter & Perry Fundamentals of Nursing, 10th ed.

Normal vital signs by age group: detailed breakdown

Neonates (0–28 days)

Heart rate: 100–160 bpm Respiratory rate: 30–60 breaths/min Systolic blood pressure: 60–90 mmHg Temperature: 97.7–100.4°F (36.5–38.0°C) SpO₂: ≥95% (after 10 minutes of life; lower in first minutes is expected)

The neonate’s cardiovascular system is still adapting from fetal circulation. Cardiac output depends almost entirely on heart rate — neonates cannot meaningfully increase stroke volume the way older hearts can. This is why a neonate’s heart rate is so much faster: it compensates for a small, poorly compliant heart.

Neonatal respiratory rate is similarly elevated because tidal volume is small. The normal range of 30–60 breaths/min can startle students who expect the adult rate of 12–20 — but in a newborn, this is physiologically appropriate. Periodic breathing (brief pauses of up to 10 seconds followed by faster breathing) is normal in neonates and does not require intervention. True apnea — a pause longer than 20 seconds, or any pause accompanied by bradycardia or color change — is not normal and warrants immediate response.

Blood pressure is low by adult standards because vascular resistance is lower in neonates. A systolic of 60–90 mmHg is expected. Blood pressure naturally rises over the first several days of life as fluid status stabilizes and the ductus arteriosus closes.

Temperature should be measured rectally in neonates for most accuracy — axillary readings may be 0.5–1.0°F lower. Hypothermia in a neonate (below 97.7°F/36.5°C) is a serious concern: neonates cannot shiver effectively and lose heat rapidly through their large body-surface-area-to-weight ratio.

Oxygen saturation: In the first 10 minutes after birth, SpO₂ naturally rises as the transition from fetal circulation completes. Target SpO₂ in the delivery room at 1 minute of life is 60–65%, rising to 85–95% by 10 minutes. After the transition period, ≥95% is the target. Persistently low SpO₂ in a neonate may indicate congenital heart disease, respiratory distress syndrome, or infection.

Clinical note: Neonates are obligate nose-breathers. Nasal congestion — from secretions or anatomic narrowing — can cause significant respiratory distress. This is a consideration that does not apply to older children or adults.

Infants (1–12 months)

Heart rate: 100–160 bpm Respiratory rate: 25–50 breaths/min Systolic blood pressure: 70–100 mmHg Temperature: 97.7–100.4°F (36.5–38.0°C) SpO₂: ≥95%

By one month of age, the neonatal transition is complete, but the infant’s cardiovascular and respiratory systems remain immature. Heart rate stays elevated relative to adults — 100–160 bpm is the expected range throughout infancy. Resting heart rates at the lower end of this range (around 100 bpm) are more common in older, larger infants; younger infants often run closer to 130–160 bpm at rest.

Respiratory rate in infants is highly variable. Infants breathe faster when crying, feeding, or mildly agitated. Assess respiratory rate in a sleeping or quietly awake infant for the most accurate baseline. A rate above 60 breaths/min in an infant at rest warrants further evaluation — this is the threshold for tachypnea and may indicate bronchiolitis, pneumonia, or congenital heart disease.

Blood pressure rises steadily through infancy as the vascular system matures and body mass increases. By 12 months, a typical infant’s systolic BP is in the 90–100 mmHg range.

For pediatric medication dosing, always calculate by weight — consult a drug dosage calculator and confirm with your pharmacist. Weight-based dosing applies from infancy through early adolescence.

Clinical note: Fever thresholds in infants require special attention. A rectal temperature ≥100.4°F (38.0°C) in an infant under 3 months is a medical emergency requiring immediate evaluation for sepsis. The same temperature in a healthy 9-month-old may be managed with watchful waiting. Age changes the clinical significance of the same number.

Toddlers (1–3 years)

Heart rate: 90–150 bpm Respiratory rate: 20–40 breaths/min Systolic blood pressure: 80–110 mmHg Temperature: 97.7–100.4°F (36.5–38.0°C) SpO₂: ≥95%

Toddlers begin to approach a more recognizable clinical profile as their cardiovascular and pulmonary systems continue maturing. Heart rates in the 90–150 bpm range are normal, and fear, crying, or activity can push rates well above 150 bpm in a healthy toddler — context matters when interpreting any single number.

Respiratory rates slow considerably from infancy, with 20–40 breaths/min being the expected range. A sleeping toddler at 25 breaths/min is normal; a resting toddler at 55 breaths/min is tachypneic and warrants investigation.

Blood pressure continues its upward trend. The AAP defines hypertension in toddlers and preschoolers as blood pressure above the 95th percentile for age, height, and sex — this is why pediatric BP interpretation requires age-specific tables rather than adult cutoffs. A systolic of 110 mmHg is the top of normal for a toddler; the same reading in a 5-year-old warrants closer monitoring.

Clinical note: Toddlers are notoriously difficult to assess. An accurate respiratory rate in a toddler requires observation for a full 60 seconds — short counts extrapolated from 15 or 30 seconds are less reliable in children due to natural rate variability. Similarly, blood pressure should be measured with an appropriately sized cuff: an adult cuff on a toddler’s arm will give falsely low readings.

Preschool children (3–5 years)

Heart rate: 80–140 bpm Respiratory rate: 20–30 breaths/min Systolic blood pressure: 80–110 mmHg Temperature: 97.7–100.4°F (36.5–38.0°C) SpO₂: ≥95%

Preschoolers show progressively narrowing vital sign ranges as their bodies mature. Heart rates slow from the toddler range, and respiratory rates begin to approach the adult zone. A preschooler at 20 breaths/min is at the low end of normal — this is the same minimum seen in adults and adolescents, reflecting the maturation of central respiratory drive.

Blood pressure norms in this age group overlap significantly with toddlers. Hypertension screening begins to take on greater significance in this age group, as primary (essential) hypertension — once considered an adult disease — is now recognized in children as young as 3–5 years, particularly in those with obesity or a strong family history.

Clinical note: Tympanic temperature measurement is generally reliable in preschool-age children. Axillary temperatures read approximately 0.5°F lower than core temperature. Oral temperatures are possible in cooperative preschoolers but remain less reliable than rectal or tympanic. For a definitive fever assessment in any young child, rectal temperature remains the gold standard — though it is rarely used in older preschoolers due to comfort and cooperation.

School-age children (6–12 years)

Heart rate: 70–120 bpm Respiratory rate: 15–25 breaths/min Systolic blood pressure: 85–120 mmHg Temperature: 97.7–100.4°F (36.5–38.0°C) SpO₂: ≥95%

School-age children are physiologically approaching adult norms in several parameters. Heart rate overlaps substantially with the adult range — a resting rate of 70–80 bpm is entirely normal in a 10-year-old. The cardiac output model shifts: cardiac output is now maintained more by stroke volume than heart rate, similar to adults.

Respiratory rates slow to 15–25 breaths/min, and tidal volume increases as the lungs grow. Lung architecture in school-age children is nearly adult in structure, though total capacity remains smaller.

Blood pressure rises steadily through this age group. A systolic of 85 mmHg in a 6-year-old and 120 mmHg in a 12-year-old can both fall within normal limits, depending on height and sex. Per AAP guidelines, blood pressure should be checked at every well-child visit from age 3 onward, and readings above the 95th percentile for age, height, and sex warrant follow-up.

Clinical note: Athletic school-age children, especially those in endurance sports, may have resting heart rates in the 50–65 bpm range — this is physiologic sinus bradycardia from training adaptation, not a pathologic finding. Always assess in context: a child with a resting HR of 55 bpm who is alert, pink, and comfortable with a strong pulse has normal sinus bradycardia. The same rate in an ill-appearing child demands immediate evaluation.

Adolescents (13–18 years)

Heart rate: 60–100 bpm Respiratory rate: 12–20 breaths/min Systolic blood pressure: 90–130 mmHg Temperature: 97.7–99.5°F (36.5–37.5°C) SpO₂: ≥95%

By adolescence, vital sign ranges are virtually identical to adult norms for heart rate, respiratory rate, and temperature. The key distinction is blood pressure: the upper limit of normal continues to shift during adolescence, and what counts as hypertension in a 13-year-old remains height- and sex-adjusted per pediatric tables rather than the flat adult cutoff.

The ACC/AHA 2017 guideline defines elevated blood pressure in adults as ≥120/80 mmHg and hypertension stage 1 as ≥130/80 mmHg. For adolescents 13 years and older, the AAP aligns with this adult threshold for simplicity: a systolic ≥130 mmHg or diastolic ≥80 mmHg is stage 1 hypertension. A 16-year-old with a consistent systolic of 135 mmHg is hypertensive by these criteria — even though 135 is a number that might go unremarked in an adult clinical setting.

Clinical note: Adolescents — particularly athletic females — are at elevated risk for relative bradycardia. Heart rates in the 45–55 bpm range may represent normal athletic adaptation or may signal a problem (eating disorder-related bradycardia, electrolyte disturbance, heart block). Context is essential: trending vital signs over time, assessing nutritional status, and comparing to prior readings all inform interpretation.

Adults (18–64 years)

Heart rate: 60–100 bpm Respiratory rate: 12–20 breaths/min Systolic blood pressure: <120 mmHg (normal); 120–129 mmHg (elevated); ≥130 mmHg (hypertension stage 1) Temperature: 97.7–99.5°F (36.5–37.5°C) SpO₂: ≥95%

Adult vital sign ranges are the most familiar from nursing education. They represent the baseline that most textbooks and clinical references describe without qualification — and the values against which deviations are most often taught.

Per the ACC/AHA 2017 guideline, the blood pressure categories for adults are:

The 2017 reclassification lowered the hypertension threshold from 140/90 mmHg (JNC 7) to 130/80 mmHg. This is clinically significant: a patient with 132/82 mmHg on a medication reconciliation review is now hypertensive by guideline definition, even if their chart says “WNL” based on older criteria.

Temperature note: The commonly cited “normal” of 98.6°F (37.0°C) is a population mean — individual baseline temperatures vary between 97.0°F and 99.0°F. The fever threshold is ≥100.4°F (38.0°C) for adults, measured orally. Rectal temperatures run approximately 0.5–1.0°F higher; axillary temperatures run 0.5–1.0°F lower.

Clinical note: Resting heart rate is a meaningful health marker in adults. Well-conditioned athletes may have resting rates below 60 bpm (sinus bradycardia from physiologic adaptation). A new onset bradycardia in a non-athlete, or a rate that has dropped significantly from the patient’s own baseline, warrants investigation regardless of whether it falls within “60–100.”

Older adults (65+ years)

Heart rate: 60–100 bpm Respiratory rate: 12–20 breaths/min Systolic blood pressure: <130/<80 mmHg (target per ACC/AHA 2017) Temperature: 97.0–99.5°F (36.1–37.5°C) SpO₂: ≥94%

Older adults present the most nuanced vital sign picture. Numeric ranges remain similar to younger adults in many parameters, but the clinical significance of values within those ranges changes.

Blood pressure: The ACC/AHA 2017 guideline recommends a systolic target of less than 130 mmHg for adults 65 and older when tolerated. However, intensive BP lowering (target <120 mmHg) is associated with increased risk of falls, syncope, and acute kidney injury in frail older adults. Clinical judgment, not guidelines alone, determines the right target for individual patients.

Temperature: Core temperature tends to decrease with age. An older adult’s normal baseline temperature may be closer to 97.0–97.5°F — meaning a temperature of 99.5°F, which would not meet fever criteria in a younger adult, represents a significant rise from baseline in an older patient. Older adults with serious infections may present without fever at all (afebrile sepsis). A “normal” temperature does not rule out infection in this population.

Heart rate: Age-related changes to the sinoatrial node reduce the maximum achievable heart rate. Chronotropic medications (beta-blockers, calcium channel blockers) are common in older adults and further blunt heart rate response. Atrial fibrillation is prevalent, making rhythm interpretation an essential complement to rate measurement.

SpO₂: The lower limit of acceptable SpO₂ for older adults is 94%, compared with 95% for younger populations. This reflects normal age-related decline in pulmonary function — reduced elasticity, decreased diffusing capacity, and increased ventilation-perfusion mismatch. A resting SpO₂ of 94–95% in a healthy 78-year-old may be their norm; the same reading in a 30-year-old with previously normal saturations warrants concern.

Respiratory rate: Respiratory rate is the most underused and undervalued vital sign — in all ages, but especially in older adults. A respiratory rate above 20 breaths/min is a reliable early warning sign of clinical deterioration, often rising hours before blood pressure drops or oxygen saturation falls. Many clinical deterioration scoring systems (NEWS, MEWS) weight respiratory rate heavily for this reason.

Clinical applications: using vital signs to recognize deterioration

Tachycardia and bradycardia thresholds

The significance of heart rate depends on context and baseline. Tachycardia thresholds by age:

• Neonates: HR >160 bpm at rest
• Infants: HR >160 bpm at rest
• Toddlers: HR >150 bpm at rest
• Preschool: HR >140 bpm at rest
• School-age: HR >120 bpm at rest
• Adolescents/Adults: HR >100 bpm at rest

Bradycardia thresholds:

• Neonates/Infants: HR <100 bpm (and <60 bpm requires immediate CPR per NRP guidelines)
• Toddlers/Preschool: HR <80 bpm
• School-age: HR <60 bpm
• Adolescents/Adults: HR <60 bpm (unless known athlete or medication effect)

Respiratory rate as an early warning

Tachypnea — elevated respiratory rate — is consistently the earliest measurable sign of clinical deterioration, preceding other vital sign changes by 6–8 hours in many studies. A respiratory rate of 22–25 in an adult or a rate approaching the upper limit for any pediatric age group should trigger increased monitoring and clinical reassessment, even when other vital signs appear stable.

Pediatric Early Warning Score (PEWS)

PEWS is a validated clinical scoring tool used in pediatric settings to identify children at risk for deterioration. It scores respiratory rate, heart rate, and oxygen saturation against age-adjusted norms — making age-specific vital sign knowledge a practical clinical requirement, not just an academic one. A 4-year-old with a heart rate of 145 bpm and a respiratory rate of 28 breaths/min may be within the upper bounds of normal for their age, or may be showing early distress — and PEWS helps nurses apply age-specific context systematically.

When to escalate

Escalate immediately for:

• Any vital sign outside the normal range for age plus clinical signs of distress (altered consciousness, poor perfusion, increased work of breathing)
• A single vital sign significantly outside the normal range without clear explanation (pain, fever, anxiety)
• Any downward trend across multiple vital signs — compensated shock often presents with heart rate rising before blood pressure falls
• Failure to respond to interventions: an infant given supplemental oxygen whose SpO₂ does not improve requires immediate escalation
• Respiratory rate above 30 in any adult or above 60 in a neonate at rest

Common confusions when applying vital sign ranges

Applying adult values to children

The single most common mistake. A blood pressure of 100/60 mmHg in a 7-year-old is perfectly normal. A blood pressure of 80/50 mmHg in an adult is hypotension. A heart rate of 120 bpm in a toddler is unremarkable. The same rate in a resting adult warrants investigation. When in doubt, reference an age-specific table rather than adult intuition.

Missing hypertension in adolescents

A 17-year-old with a consistent blood pressure of 128/82 mmHg may go unrecognized if nurses apply only adult “normal” thresholds. By ACC/AHA 2017 criteria, this is stage 1 hypertension, warranting lifestyle counseling and follow-up. Adolescent hypertension is underdiagnosed in large part because clinicians expect it to be an adult disease.

Fever threshold confusion: axillary vs. rectal

Fever thresholds vary by measurement site:

• Rectal: ≥100.4°F (38.0°C) — most accurate; gold standard in infants under 3 months
• Oral: ≥100.0°F (37.8°C)
• Axillary: ≥99.0°F (37.2°C) — least accurate; acceptable for screening only
• Tympanic: ≥100.4°F (38.0°C) — acceptable from 6 months onward; unreliable in neonates

An axillary temperature of 99.2°F is technically a fever by the axillary threshold — but this is often documented as “no fever” by students comparing it to the oral or rectal cutoff. Using the wrong threshold for the wrong site understates or overstates fever in a clinically meaningful way.

Treating the normal-looking number in a sick patient

A blood pressure of 90/60 mmHg in an adult is hypotension. In a patient with chronic hypertension whose baseline runs 160/95, a reading of 110/70 mmHg may represent relative hypotension — a 30% drop from baseline — even though the absolute number falls within the population “normal” range. Always compare to the patient’s own documented baseline when interpreting vital signs.

Related references

Vital signs are one component of a complete clinical assessment. For deeper reference on related topics:

• Head-to-toe assessment: The full systematic physical assessment framework — vital signs are the starting point, and this guide covers every body system that follows.
• APGAR score: The standard tool for evaluating neonatal vital status immediately after delivery, including pulse and respiration scoring.
• Glasgow Coma Scale: The GCS quantifies neurological status — complement vital signs with GCS scoring in any patient with altered consciousness.
• Nursing lab values: Normal lab values by age (CBC, metabolic panel, ABGs) are the laboratory complement to bedside vital sign assessment.

For pediatric patients, weight-based dosing is calculated based on accurate weight in kilograms. Use a drug dosage calculator to verify calculations before administration.