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Fundamentals of Nursing Practice · Assessment

Vital Signs and Pain Assessment

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On this page 7 sections
  1. In 30 seconds
  2. Why this matters
  3. The college version
  4. Eli explains
  5. Worked example
  6. Key takeaway
  7. Study tools

In 30 seconds

—temperature, pulse, , blood pressure, plus pain and pulse oximetry—are quick, repeatable measurements of how the body is functioning. Temperature is measured by several routes, with fever and hypothermia at either extreme. Pulse is described by rate, rhythm, and amplitude; respirations by rate, depth, and rhythm; and blood pressure by systolic and diastolic values, , and orthostatic change. Pulse oximetry estimates SpO2, and pain is assessed systematically with PQRST and COLDSPA.

Why this matters

Vital signs are often the first data in a legal record; accurate measurement and documentation are part of safe, accountable practice. Respecting pain honors autonomy and dignity, and failing to assess or treat pain is a quality and safety concern. Nurses use correct equipment and technique, recognize invalid readings, and never invent or round a value to look "normal"—falsifying vital signs is a serious breach of trust and duty. Techniques, ranges, and standards vary by setting and institution.

The college version

1. Temperature

Body temperature reflects the balance between heat produced and lost (about 36.5–37.5 °C / 97.6–99.6 °F, varying by route). Oral is common and convenient; tympanic (ear) reads quickly and reflects core; rectal is closest to core but invasive; axillary is safe but least accurate; temporal (forehead) is quick and noninvasive. Fever (pyrexia) is an elevated temperature, usually the body's defense against infection; hypothermia is a dangerous drop in core temperature. Both extremes need monitoring and qualified evaluation when severe.

2. Pulse and respirations

The pulse is the rhythmic expansion of an artery with each heartbeat, counted at a peripheral site (wrist) or the apical site (over the heart, used for irregular rhythms). It is described by rate (beats per minute), rhythm (regular or irregular), and amplitude (strength). Respirations are breaths per minute, described by rate, depth, and rhythm. Abnormal patterns: tachypnea (fast), bradypnea (slow), Cheyne-Stokes (deep breaths fading to a pause), and Kussmaul (deep, rapid, labored, often in metabolic problems such as diabetic ketoacidosis). Nurses count respirations without the client noticing.

3. Blood pressure, pulse oximetry, and pain

Blood pressure is the force of blood against artery walls: systolic is the peak during contraction, diastolic the pressure between beats. Korotkoff sounds are the taps heard as the cuff deflates—first sound marks systolic, disappearance marks diastolic. Orthostatic pressure compares lying, sitting, and standing; a drop on standing signals orthostatic hypotension and fall risk. Pulse oximetry estimates the percentage of hemoglobin saturated with oxygen (SpO2, normally 95–100%), but is unreliable with poor circulation, cold fingers, nail polish, movement, or carbon monoxide. Because pain is whatever the client says it is, pain assessment relies on self-report. PQRST = Provocation/palliation, Quality, Region/radiation, Severity, Timing. COLDSPA = Character, Onset, Location, Duration, Severity, Pattern, Associated factors.

How it works

  1. Obtain each value with correct technique; note route, position, activity.
  2. Compare to the client's baseline and age norms.
  3. Describe, don't just record—rhythm, amplitude, depth, pattern, and pain quality add meaning.
  4. Look at trends, since a single value may mislead.
  5. Report and escalate abnormal or worsening values promptly.

Common confusions

Do not confuseWithDifference
TachypneaBradypneaFast vs slow breathing
Cheyne-StokesKussmaulCyclic fading vs deep, rapid, labored
SystolicDiastolicPeak vs resting pressure
HypoxemiaHypoxiaLow blood oxygen vs low tissue oxygen
Apical pulsePeripheral pulseHeard over the heart vs felt at an artery

Memory aids

"Hot, Beat, Breathe, BP, Hurt"—the vital signs in order: temperature, pulse, respirations, blood pressure, pain. For pain detail, PQRST: Provocation, Quality, Region/radiation, Severity, Timing.

Quick review

Topic Recap

  • Vital signs are the body's dashboard, read in context and trend.
  • Temperature uses oral, tympanic, rectal, axillary, and temporal routes; fever and hypothermia mark the extremes.
  • Pulse is rate, rhythm, amplitude (apical or peripheral); respirations are rate, depth, rhythm with distinctive abnormal patterns.
  • Blood pressure pairs systolic and diastolic via Korotkoff sounds, with orthostatic checks; pulse oximetry estimates SpO2 with limits.
  • Pain is assessed by self-report using PQRST or COLDSPA.

Knowledge Check

  1. Which temperature route is closest to core, and which is least accurate?
  2. What is the difference between tachypnea and bradypnea?
  3. What do the first and last Korotkoff sounds mark?
  4. Why might a pulse oximeter reading be unreliable?
  5. What does each letter of PQRST stand for?

Answers and Rationales

  1. Answer: Rectal is closest to core; axillary is least accurate. Why: The route shapes how the reading is interpreted.
  2. Answer: Tachypnea is fast; bradypnea is slow. Why: Opposite deviations with different causes and risks.
  3. Answer: First sound = systolic; sounds disappear = diastolic. Why: These define the two numbers.
  4. Answer: Poor circulation, cold fingers, nail polish, movement, carbon monoxide. Why: SpO2 is a screen, not a direct measure.
  5. Answer: Provocation/palliation, Quality, Region/radiation, Severity, Timing. Why: Converts a vague complaint into detail.
Eli, the EliExplains learning guide

Eli explains

The same idea, in plain words

Explain it like I’m 10

Think of vital signs as a car's dashboard gauges. You cannot see the engine, but the temperature gauge and speedometer tell you whether it is running well. Vital signs are the body's dashboard: one glance shows whether the heart, lungs, and temperature regulation are working normally.

The comparison stops being exact because a car's gauges measure one thing directly, while a person's "gauges" change with activity, stress, pain, illness, medications, and age. A child's pulse is faster than an adult's, and one abnormal reading may mean nothing while a trend means everything—so nurses read vital signs in context and over time.

Simple Example

A client who just ran upstairs has a faster pulse and breathing than one who rested for an hour. Both readings are "correct"; only context turns the numbers into meaning.

Worked example

  1. Observe and measure: Obtain temperature, pulse, respirations, blood pressure, and SpO2, noting the client's appearance and activity.
  2. Assess: Compare to the client's baseline and age norms; explore pain with PQRST or COLDSPA.
  3. Document: Record values with route, position, and factors affecting interpretation.
  4. Communicate: Report abnormal or trending values using SBAR.
  5. Escalate: Very high fever, extreme blood pressure, falling SpO2, abnormal breathing, or severe pain requires prompt qualified evaluation per policy.

Key takeaways

  • High yield: Pain is often the "fifth vital sign," and self-report is its most reliable measure.
  • High yield: Rectal temperature is closest to core; axillary is least accurate.
  • High yield: Tachypnea is fast, bradypnea slow; Cheyne-Stokes fades to a pause, Kussmaul is deep and labored.
  • High yield: Systolic is the first Korotkoff sound; diastolic is when the sounds disappear.
  • High yield: Orthostatic blood pressure compares lying, sitting, standing—a drop signals fall risk.
  • High yield: SpO2 is an estimate—poor circulation, cold fingers, nail polish, and carbon monoxide make it unreliable.
  • PQRST and COLDSPA both structure a pain history.
  • A trend matters more than a single abnormal value.

Keep learning

Ready to build on this? Continue to the next lesson.

Study tools & related lessonsYou’ll learn to · Key vocabulary · Related

You’ll learn to

  • Identify the core vital signs and normal adult ranges for temperature, pulse, respirations, and blood pressure.
  • Compare temperature routes (oral, tympanic, rectal, axillary, temporal) and describe fever and hypothermia.
  • Describe pulse, respiration, and blood-pressure characteristics, including abnormal patterns (tachypnea, bradypnea, Cheyne-Stokes, Kussmaul, orthostatic changes).
  • Explain pulse oximetry (SpO2) and use PQRST and COLDSPA to structure a pain assessment.

Key vocabulary

Vital signs
Temperature, pulse, respirations, blood pressure (+ pain, SpO2)
Temperature routes
Oral, tympanic, rectal, axillary, temporal
Fever / hypothermia
High / dangerously low core temperature
Pulse (apical, peripheral)
Heartbeats at an artery or over the heart
Pulse rate, rhythm, amplitude
Speed, regularity, strength
Respirations
Breaths per minute with rate, depth, rhythm
Tachypnea / bradypnea
Fast / slow breathing
Cheyne-Stokes / Kussmaul
Cyclic fading / deep, rapid, labored breathing
Systolic / diastolic
Peak / resting arterial pressure
Korotkoff sounds
Taps marking systolic and diastolic
Orthostatic BP
Lying, sitting, standing comparison
Pulse oximetry / SpO2
Estimate of blood oxygen saturation
Pain assessment (PQRST, COLDSPA)
Structured pain questions
Self-report
The client's own pain description

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