Vital Signs Made Easy: How to Measure and Interpret Them

Checking vital signs is one of the first things every nurse learns. But doing it right — and understanding what the numbers mean — is what makes you a safe, confident caregiver.

This simple guide will help you measure each vital sign step-by-step, know what normal and abnormal values mean, and spot when your patient needs help fast.


🩺 What Are Vital Signs?

Vital signs are key numbers that show how well the body is working. They tell you about blood circulation, breathing, temperature, and sometimes pain.

The 5 basic vital signs are:
1️⃣ Temperature (T)
2️⃣ Pulse (P)
3️⃣ Respiratory rate (RR)
4️⃣ Blood pressure (BP)
5️⃣ Oxygen saturation (SpO₂)

Many nurses also include pain as the “6th vital sign.”


🌡️ 1️⃣ Temperature

What it shows:
Body temperature helps you find fever, infection, or heat loss.

Normal range:

  • 97.8°F to 99.1°F (36.5°C to 37.3°C)

How to measure:

  • Oral (under tongue) — common for adults.
  • Axillary (under arm) — easy but less accurate.
  • Tympanic (ear) — quick for kids.
  • Rectal — most accurate, often for babies.

What’s abnormal:

  • Fever: > 100.4°F (38°C) → may mean infection.
  • Hypothermia: < 95°F (35°C) → may mean cold exposure, shock, or sepsis.

Nursing tips:

  • Wait 15 minutes after hot/cold drinks for oral temp.
  • Always compare to patient’s normal baseline.

❤️ 2️⃣ Pulse (Heart Rate)

What it shows:
Heartbeats per minute show how well the heart pumps blood.

Normal range:

  • Adults: 60–100 bpm
  • Athletes: may be lower
  • Children: higher than adults

How to measure:

  • Use index and middle fingers (not thumb).
  • Count for 30 seconds and double it.
  • Common sites: radial (wrist), carotid (neck), apical (stethoscope over heart).

What’s abnormal:

  • Bradycardia: < 60 bpm (can be normal for athletes)
  • Tachycardia: > 100 bpm (may mean fever, pain, dehydration)

Nursing tips:

  • If irregular, count a full minute and listen apically.
  • Check for strength and regularity, not just number.

🌬️ 3️⃣ Respiratory Rate

What it shows:
Breaths per minute show how well the patient is breathing.

Normal range:

  • Adults: 12–20 breaths/minute

How to measure:

  • Watch chest rise and fall.
  • Count for 30 seconds quietly (patients may breathe differently if they know you’re counting!).

What’s abnormal:

  • Bradypnea: < 12 (may mean sedation, drug overdose)
  • Tachypnea: > 20 (may mean fever, pain, anxiety, or lung issues)

Nursing tips:

  • Look for signs like labored breathing, cyanosis, or use of neck muscles.

💉 4️⃣ Blood Pressure

What it shows:
How much pressure blood puts on artery walls — tells you about circulation and heart health.

Normal range:

  • Systolic: 90–120 mmHg
  • Diastolic: 60–80 mmHg

How to measure:

  • Patient resting, arm at heart level.
  • Correct cuff size.
  • Inflate cuff, listen for Korotkoff sounds.

What’s abnormal:

  • Hypertension: > 140/90 mmHg (long-term → stroke, heart disease)
  • Hypotension: < 90/60 mmHg (may mean shock, dehydration)

Nursing tips:

  • Always compare to patient’s normal BP.
  • Check both arms for differences.
  • Recheck manually if automatic reading seems wrong.

🫧 5️⃣ Oxygen Saturation (SpO₂)

What it shows:
How much oxygen the blood carries.

Normal range:

  • 95%–100% on room air.

How to measure:

  • Use a pulse oximeter on fingertip, earlobe, or toe.

What’s abnormal:

  • Hypoxia: < 90% (may mean lung or heart trouble)

Nursing tips:

  • Cold fingers or nail polish can affect readings.
  • Compare to patient’s baseline, especially for COPD patients.

😣 Bonus: Pain as the 6th Vital Sign

Why it matters:
Pain affects heart rate, BP, and recovery.

How to measure:

  • Use a pain scale: 0 (no pain) to 10 (worst pain).
  • Ask: “Where is the pain? How does it feel? What makes it better?”

Nursing tips:

  • Believe the patient’s report.
  • Reassess after giving pain medicine.

🩹 How to Document Vital Signs

✔️ Record numbers clearly in the chart.
✔️ Note the time and method (oral temp, radial pulse).
✔️ Write extra info: “BP 130/80, sitting position, left arm.”


🚩 When to Worry

Call for help if you see:

  • Sudden drop in BP or pulse.
  • High fever not responding to meds.
  • Low oxygen despite O₂ therapy.
  • Fast breathing with distress.

Always trust your instincts — if something feels off, reassess and get help.


📋 Vital Signs Cheat Sheet

Vital SignNormal Adult RangeWhat to Watch
Temp97.8–99.1°F (36.5–37.3°C)Fever, hypothermia
Pulse60–100 bpmBradycardia, tachycardia
Resp. Rate12–20/minBradypnea, tachypnea
BP90–120/60–80 mmHgHypotension, hypertension
SpO₂95–100%Hypoxia

🗂️ Key Takeaways

✔️ Always compare to your patient’s normal values.
✔️ Take time to measure each vital sign correctly.
✔️ Use vital signs to spot problems early — before they become an emergency.

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