Vital Signs Assessment

Key Points

  • Five vital signs: Temperature (T), Pulse (P), Respiratory Rate (RR), Blood Pressure (BP), SpO2 — pain is often called the “fifth vital sign” in clinical practice
  • Delegation: Vital signs may be delegated to UAP for stable patients per state NPA and agency policy — nurse remains accountable for interpreting results and following up on deviations
  • Obtain vital signs at admission, routine interval, and any condition-trigger event (for example suspected infection, fall, or relevant medication change).
  • Ordered frequency is the minimum monitoring cadence; any change in condition warrants immediate reassessment.
  • Typical cadence varies by setting and acuity (for example acute care often every 4-8 hours, critical-care/postprocedure as frequently as every 15-60 minutes, outpatient at visit start, and long-term-care daily or as needed).
  • Normal adult BP: <120/80 mmHg (2017 AHA/ACC guidelines); hypertension = ≥130/80 mmHg
  • Normal adult pulse: 60–100 bpm; assess rate, rhythm, force (0–3+ scale), and bilateral equality
  • Apical pulse: Most accurate; required before administering cardiac medications
  • If radial pulse site is inaccessible (for example cast, arterial line, amputation, or dressing), use apical auscultation and assess other perfusion sites as indicated.
  • Orthostatic hypotension: Drop of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing — significant fall risk, especially in older adults

Equipment

  • Thermometer (oral, tympanic, axillary, rectal, or temporal) with probe covers
  • Pulse oximeter with appropriate probe site
  • Stethoscope
  • Sphygmomanometer (blood pressure cuff) — appropriately sized for patient arm
  • Watch with second hand or digital timer
  • Gloves (for rectal temperature)

Normal Ranges Reference

Temperature by Route

RouteNormal RangeCompared to Oral
Oral35.8–37.3°C (96–99°F)Reference standard
Axillary34.8–36.3°C (94.6–97.3°F)Lower than oral
Tympanic36.1–37.9°C (96.9–100.2°F)Higher than oral
Rectal36.8–38.2°C (98.2–100.7°F)Higher than oral — gold standard for infants
Temporal35.2–36.7°C (95.3–98°F)Lower than oral

Pulse by Age

Age GroupNormal Range (bpm)
Preterm120–180
Newborn (0–1 month)100–160
Infant (1–12 months)80–140
Toddler (1–3 years)80–130
Preschool (3–5 years)80–110
School age (6–12 years)70–100
Adolescent/Adult (≥13 years)60–100
  • Well-conditioned adolescents and athletes may have resting rates around 40-50 bpm with adequate perfusion.

Respiratory Rate by Age

AgeNormal Range (breaths/min)
Infant30–60
Toddler20–30
Preschooler20–25
School age14–22
Adolescent12–18
Adult12–20

Blood Pressure (Adult Screening Categories)

CategorySystolic (mmHg)Diastolic (mmHg)
Hypotension<90<60
Normal90–11960–80
Elevated120–129≤80
Stage I Hypertension130–13980–89
Stage II Hypertension≥140≥90

Oxygen Saturation (SpO2)

  • Typical healthy range: 96-100%
  • COPD patients: 88-93% may represent expected baseline
  • SpO2 is an estimate; severe anemia and poor peripheral perfusion can produce falsely low readings.
  • Pulse oximetry can be intermittent or continuous based on patient condition and clinical order.

Immediate Reporting Triggers (Adult)

  • Temperature greater than 38°C (100.4°F), noting older-adult baseline temperatures may be lower (about 36°C/96°F can be typical).
  • Pulse less than 60 bpm or greater than 100 bpm at rest.
  • Respiratory rate less than 12 or greater than 20 breaths/min.
  • Blood pressure outside normal range or with concerning symptoms.

Procedure Steps

  1. Gather equipment — select thermometer route appropriate for patient age, level of consciousness, and condition; ensure BP cuff fits correctly (too small → falsely high reading; too large → falsely low reading)
  2. Confirm timing/indication and prepare patient — verify ordered/routine schedule, monitoring parameters, trigger context (new symptoms, post-fall, medication-related reassessment), and relevant prior trends/history; screen for route/site restrictions (for example avoid BP in mastectomy/lymphedema-risk arm, avoid oral temperature with oral trauma, avoid compromised pulse sites); then perform hand hygiene, explain procedure, and ensure patient has been resting; temperature: wait 15–25 minutes after hot/cold intake, smoking, or gum chewing before oral measurement; blood pressure: avoid caffeine/smoking/exertion for about 30 minutes when feasible, keep patient quiet, and allow at least 5 minutes seated rest
  3. Obtain temperature — insert thermometer per route-specific technique; document route alongside temperature value (e.g., “37.0°C oral”)
  4. Assess pulse — palpate radial pulse for 60 full seconds if irregular; assess rate, rhythm (regular/irregular), force (0 = absent, 1+ = weak/thready, 2+ = normal, 3+ = bounding), and bilateral equality. If radial site is inaccessible or too weak/rapid to interpret reliably, auscultate apical pulse for one full minute and consider brachial/femoral palpation to evaluate peripheral perfusion; for cardiac medications (for example digoxin): use apical method
  5. Count respiratory rate — count for 60 seconds while appearing to assess pulse (to prevent patient from altering breathing); assess rhythm and depth/quality (no accessory muscle use, no nasal flaring); if chest movement is difficult to observe, auscultate one lung field with stethoscope for 60 seconds
  6. Obtain SpO2 — apply probe to finger, toe, or earlobe; remove nail polish if present; warm extremity if cold/vasoconstricted; read value after stable waveform displayed; use continuous monitoring when ordered for unstable or high-risk patients
  7. Measure blood pressure — wrap cuff snugly around upper arm (brachial artery); inflate 30 mmHg above point where radial pulse disappears; deflate at 2–3 mmHg/second; first Korotkoff sound = systolic; last Korotkoff sound = diastolic
  8. Assess for orthostatic hypotension if indicated — measure BP and pulse supine, then immediately standing, then again at 3 minutes standing; orthostatic hypotension = SBP drop ≥20 mmHg or DBP drop ≥10 mmHg; pulse increase ≥30 bpm also significant
  9. Analyze and document results — immediately compare to patient’s baseline and age-specific normals; document with route (temperature), position (BP), room-air versus supplemental-oxygen context for SpO2, and clinical context; if monitor-derived values do not fit bedside findings, manually recheck and document discrepancy resolution
  10. Report deviations — immediately notify provider or instructor of any out-of-range vital sign; when escalating change in status, report a complete current set for full clinical picture; initiate emergency response for signs of deterioration (see tanners-clinical-judgment-model-in-nursing-practice)

Common Errors

  • Taking oral temperature <15 minutes after hot/cold intake → falsely elevated or decreased reading
  • BP cuff too small → falsely HIGH reading; cuff too large → falsely LOW reading
  • Palpating both carotid arteries simultaneously → risk of decreased cerebral blood flow; always assess one side at a time
  • Nail polish on SpO2 probe finger → falsely LOW SpO2 reading
  • Counting respiratory rate with patient aware → patient may voluntarily alter breathing pattern
  • Ignoring site contraindications (for example BP cuff on affected post-mastectomy arm) preventable harm and invalid readings
  • Continuing to use suspected faulty equipment repeated invalid data; remove from service, label do not use, and report for biomed check