Contents · 9 sections
Normal values for pulse, blood pressure, and respiration in a child change every year of life, making "adult" benchmarks of 60–80 bpm and 120/80 useless for pediatrics. Below are age-specific tables, formulas frequently tested on the propedeutics of childhood diseases exam, and guidelines on when a deviation from the norm is physiological versus an indication for workup.
Heart rate
| Age | Resting HR, bpm (normal) | Mean |
|---|---|---|
| Neonatal | 120–160 | 140 |
| 1–6 mo | 110–150 | 130 |
| 6–12 mo | 100–140 | 120 |
| 1–2 years | 95–130 | 110 |
| 2–5 years | 85–120 | 100 |
| 5–8 years | 75–110 | 90 |
| 8–12 years | 70–100 | 85 |
| 12–15 years | 60–95 | 75 |
| Over 15 years | 60–80 | 70 |
In children under one year, pulse should be counted for a full minute, as respiratory sinus arrhythmia and the reaction to examination create a scatter of 20–30 beats. Tachycardia is defined as exceeding the upper limit of the age-specific resting norm on repeat measurement; HR increases by approximately 10 beats per minute for each degree of fever, which is not pathological. Bradycardia in a child is always an indication for an ECG: in children, it is more commonly secondary (hypoxia, increased intracranial pressure, heart blocks).
Respiratory rate
| Age | Resting RR, per min | RR : HR ratio |
|---|---|---|
| Neonatal | 40–60 | 1 : 2,5–3 |
| 1–12 mo | 30–40 | 1 : 3–3,5 |
| 1–3 years | 25–30 | 1 : 3,5–4 |
| 4–6 years | 22–25 | 1 : 4 |
| 7–10 years | 18–22 | 1 : 4 |
| 11–15 years | 16–20 | 1 : 4–4,5 |
In neonates, breathing is irregular: pauses of up to 5–10 seconds (periodic breathing) are normal, whereas apnea lasting longer than 20 seconds or accompanied by bradycardia and cyanosis is not. WHO tachypnea criteria for pneumonia diagnosis: ≥60/min up to 2 months, ≥50 at 2–12 months, ≥40 from 1 to 5 years. The RR to HR ratio is useful in fever: if respiration accelerates disproportionately to the pulse (1 : 2 or less), pulmonary involvement should be suspected.
Blood pressure
| Age | Systolic, mmHg | Diastolic, mmHg |
|---|---|---|
| Neonatal | 60–75 | 35–50 |
| 1–12 mo | 75–95 | 45–60 |
| 1–3 years | 85–100 | 50–65 |
| 4–6 years | 90–105 | 55–70 |
| 7–10 years | 95–110 | 60–75 |
| 11–14 years | 100–120 | 65–80 |
| 15–17 years | 105–125 | 65–85 |
Formulas for calculating BP in children
Exams test approximate formulas used in the absence of percentile charts:
- Children over 1 year (Popov): SBP = 90 + 2n, DBP = 60 + n, where n is age in years. For 7 years: 104/67.
- Children under 1 year: SBP = 76 + 2m, where m is age in months; DBP is 1/2 to 2/3 of systolic.
- Lower limit of normal for systolic (for assessing hypotension in shock): 70 + 2n for children aged 1–10; less than 60 in neonates, less than 70 under one year.
Precise evaluation is based on percentile charts adjusted for sex, age, and height: arterial hypertension in a child is defined as SBP and/or DBP at or above the 95th percentile on three measurements on different days; the 90th–95th percentile is "high normal". For adolescents aged 13 and older, adult thresholds of 130/80 and higher are used.
How to measure BP in a child
The cuff bladder should cover 2/3 of the upper arm length (with a width of 40% of the upper arm circumference); a narrow cuff overestimates the result, while a wide cuff underestimates it. The child should sit quietly for 5 minutes, arm supported at heart level. Measure three times with a 1–2 minute interval, taking the average of the last two readings. In children under 3 years old, BP is not routinely measured during examinations; indications include prematurity, congenital heart and renal defects, and medications that raise blood pressure.
When a deviation is normal
- Respiratory sinus arrhythmia in children and adolescents — pulse acceleration during inspiration and deceleration during expiration; disappears during breath-holding.
- Tachycardia during crying, feeding, fever, or after active play.
- Bradycardia in conditioned adolescent athletes (down to 50 bpm at rest) with a normal ECG.
- Blood pressure difference between arms of up to 10 mmHg; pressure in the legs is 10–20 mmHg higher than in the arms (the reverse ratio is an indication to rule out coarctation of the aorta).
When a deviation is pathological
Persistent resting tachycardia without fever — anemia, hyperthyroidism, myocarditis, rhythm disorders. Tachypnea with chest retractions — respiratory failure. Hypertension in a child under 10 is secondary in most cases: renal disease, coarctation, endocrine causes — requires workup rather than observation. Hypotension with tachycardia and capillary refill time greater than 2 seconds are signs of shock; children's blood pressure drops late, so clinical assessment relies primarily on pulse and perfusion.
Exam cheat sheet
| Age | HR | RR | BP |
|---|---|---|---|
| Neonatal | 140 | 40–60 | 70/40 |
| 1 year | 120 | 30–35 | 90/60 |
| 5 years | 100 | 25 | 100/65 |
| 10 years | 85 | 20 | 110/70 |
| 15 years | 75 | 16–18 | 120/75 |
Frequently asked questions
What is the pulse of a neonate during sleep? 20–30 beats lower than while awake — 100–120 is considered normal if the child is pink and breathing evenly.
How do WHO norms differ from Russian textbooks? Not fundamentally: Russian textbooks (Mazurin, Vorontsov) provide mean values, while the WHO and AAP provide ranges and percentiles. Use formulas and means for exam questions, and percentile charts in clinical practice.
What is the formula for heart rate? There is no universally accepted formula; guideline: after one year of age, HR ≈ 100 − 2n up to 10 years, after which it approaches adult values.
See also: Child physical development: norms and centiles · Formulas in pediatrics · Apgar score · Pediatrics Course