Vital Signs – Complete Detailed Notes for Nursing Students
Temperature, Pulse, Respiration, Blood Pressure, SpO₂, Pain and Pupillary Assessment with Clinical Assessment Sequence
Vital signs are fundamental components of nursing assessment. They provide important information about the patient's physiological condition and may help identify early clinical deterioration.
These notes are useful for BSc Nursing, GNM, ANM, NORCET, AIIMS Nursing, Nursing Foundation and other nursing examinations.
What Are Vital Signs?
Vital signs are measurable physiological parameters that provide information about the basic functioning of the body.
The traditional four vital signs are:
- Temperature
- Pulse
- Respiration
- Blood Pressure
Modern clinical assessment commonly also includes oxygen saturation (SpO₂). Pain is frequently taught as the fifth vital sign, while pupillary assessment is particularly important during neurological assessment.
Vital signs should never be interpreted as isolated numbers. Always consider the patient's age, baseline values, symptoms, disease condition, medications, activity level and overall clinical appearance.
📚 Table of Contents
- 1. Temperature
- 2. Pulse
- 3. Respiration
- 4. Blood Pressure
- 5. Oxygen Saturation – SpO₂
- 6. Pain Assessment
- 7. Pupillary Assessment
- Normal Adult Reference Values
- Factors Affecting Vital Signs
- Clinical Assessment Sequence
- Condition-Wise Assessment Sequence
- Nursing Responsibilities
- Documentation
- Important Current Clinical Points
- High-Yield Exam Revision
- Frequently Asked Questions
- 10 MCQs
- Answers and Explanations
1. Temperature
Definition
Body temperature is the degree of heat maintained by the body through a balance between heat production and heat loss.
The hypothalamus plays the major role in thermoregulation.
Normal Temperature
Normal temperature varies between individuals and can change according to the time of day, measurement site, age, activity and health status.
Temperature Measurement Sites
- Oral
- Axillary
- Rectal
- Tympanic
- Temporal artery
Temperature Conversion
Example: 37°C = 98.6°F
Fever
Fever is an elevation of body temperature associated with a change in the thermoregulatory set point, commonly occurring with infection or inflammation.
A temperature of approximately 38°C (100.4°F) or higher is commonly considered fever in adults, although interpretation depends on measurement method and clinical context.
Hypothermia
Hypothermia occurs when core body temperature falls below approximately 35°C.
Hyperthermia
Hyperthermia occurs when body temperature rises because heat production or environmental heat exceeds the body's ability to dissipate heat.
Factors Affecting Temperature
- Age
- Exercise
- Time of day
- Hormonal changes
- Infection
- Environmental temperature
- Stress
- Medications
- Dehydration
- Metabolic activity
2. Pulse
Definition
Pulse is the palpable expansion of an artery produced by cardiac contraction.
Normal Adult Pulse
Pulse Sites
- Temporal
- Carotid
- Apical
- Brachial
- Radial
- Femoral
- Popliteal
- Posterior tibial
- Dorsalis pedis
Do not palpate both carotid arteries simultaneously.
Characteristics of Pulse
- Rate
- Rhythm
- Amplitude / Volume
- Equality
- Tension
Tachycardia
Resting adult heart rate >100 bpm is generally described as tachycardia.
Possible causes include:
- Fever
- Pain
- Anxiety
- Exercise
- Hypovolemia
- Anemia
- Hypoxia
- Infection
- Arrhythmias
Bradycardia
Resting adult heart rate <60 bpm is generally described as bradycardia.
A low heart rate may be normal in trained athletes and some healthy individuals.
Pulse Deficit
Pulse deficit is the difference between the apical heart rate and the peripheral pulse rate.
Radial Pulse Assessment Procedure
3. Respiration
Definition
Respiratory rate is the number of breaths taken by a person in one minute.
Normal Adult Respiratory Rate
Characteristics of Respiration
- Rate
- Rhythm
- Depth
- Effort
- Character
- Breath sounds when indicated
- Use of accessory muscles
Important Terms
Eupnea
Normal effortless breathing.
Tachypnea
Abnormally rapid breathing.
Bradypnea
Abnormally slow breathing.
Apnea
Absence of breathing.
Dyspnea
Difficulty or discomfort in breathing.
Orthopnea
Difficulty breathing when lying flat.
Abnormal Respiratory Patterns
Cheyne-Stokes Respiration
Gradual increase in respiratory depth followed by gradual decrease and a period of apnea.
Kussmaul Respiration
Deep and usually rapid breathing classically associated with severe metabolic acidosis such as diabetic ketoacidosis.
Biot's / Ataxic Respiration
Irregular breathing with periods of apnea, associated with serious neurological dysfunction.
Respiratory Assessment Procedure
- Ensure the patient is comfortable.
- Observe chest or abdominal movement.
- Count respirations.
- Assess rate and rhythm.
- Assess depth.
- Observe respiratory effort.
- Look for accessory muscle use.
- Assess colour and signs of respiratory distress.
- Measure SpO₂ when indicated.
- Document findings.
4. Blood Pressure
Definition
Blood pressure is the force exerted by circulating blood against the walls of the arteries.
Systolic Blood Pressure
The pressure in the arteries during ventricular contraction.
Diastolic Blood Pressure
The arterial pressure during ventricular relaxation.
Blood Pressure Example
120 = Systolic BP
80 = Diastolic BP
Adult Blood Pressure Categories
| Category | Systolic | Diastolic |
|---|---|---|
| Normal | <120 mmHg | <80 mmHg |
| Elevated | 120–129 mmHg | <80 mmHg |
| Stage 1 Hypertension | 130–139 mmHg | 80–89 mmHg |
| Stage 2 Hypertension | ≥140 mmHg | ≥90 mmHg |
Pulse Pressure
Example:
120 − 80 = 40 mmHg
Mean Arterial Pressure
For BP 120/80:
MAP ≈ 80 + 1/3(40) ≈ 93 mmHg
Correct BP Measurement
Orthostatic Blood Pressure
Orthostatic or postural blood pressure assessment compares BP and pulse in different positions, commonly lying, sitting and/or standing, according to the clinical protocol.
It may be useful when evaluating symptoms such as dizziness, syncope or suspected volume depletion.
A single abnormal BP reading should not automatically be interpreted as a diagnosis. Consider measurement accuracy, symptoms, repeated readings and clinical context.
5. Oxygen Saturation – SpO₂
Definition
SpO₂ is the estimated percentage of haemoglobin saturated with oxygen, measured non-invasively using a pulse oximeter.
Clinical Uses
- Respiratory disorders
- Pneumonia
- Asthma
- COPD
- Cardiac conditions
- Critical illness
- Perioperative monitoring
- Oxygen therapy monitoring
Do not assume that one SpO₂ target applies to every patient. Oxygen saturation targets depend on the patient's clinical condition and prescribed treatment.
Factors Affecting Pulse Oximeter Accuracy
- Cold extremities
- Poor peripheral perfusion
- Patient movement
- Incorrect probe placement
- Excessive ambient light
- Device limitations
- Abnormal haemoglobin states
Nursing Assessment
- Check probe placement.
- Ensure adequate signal.
- Assess peripheral perfusion.
- Allow the reading to stabilize.
- Assess the patient's respiratory condition.
- Correlate SpO₂ with respiratory rate and work of breathing.
- Document oxygen therapy when applicable.
6. Pain Assessment
Pain is commonly referred to as the fifth vital sign in nursing education. However, pain is subjective and should be assessed using an appropriate validated scale and clinical history.
PQRST / OPQRST Pain Assessment
| Component | Meaning |
|---|---|
| P – Provocation/Palliation | What causes or relieves the pain? |
| Q – Quality | What does the pain feel like? Sharp, burning, crushing, etc. |
| R – Region/Radiation | Where is the pain? Does it spread? |
| S – Severity | How severe is the pain? |
| T – Timing | When did it start? Is it continuous or intermittent? |
Common Pain Scales
- Numeric Rating Scale: commonly 0–10
- Visual Analogue Scale: visual continuum of pain intensity
- Wong-Baker Faces: useful for selected children and patients who have difficulty using numbers
- FLACC: useful for selected non-verbal or young children according to clinical protocol
Pain Reassessment
After a pain-management intervention, reassess pain according to the intervention, medication onset and institutional protocol.
7. Pupillary Assessment
Pupillary assessment is an important component of neurological assessment. It can provide information about neurological function and may help identify changes requiring urgent evaluation.
What Should Be Assessed?
- Pupil size
- Pupil shape
- Pupil symmetry
- Reaction to light
- Direct light response
- Consensual light response
- Accommodation when indicated
PERRLA
Direct Light Reflex
When light is directed into one eye, the pupil of that same eye constricts.
Consensual Light Reflex
When light is directed into one eye, the pupil of the opposite eye also constricts.
Accommodation
Accommodation refers to the adjustment of the eyes for viewing objects at different distances. Pupillary constriction normally occurs during near focusing.
Abnormal Pupillary Findings
Anisocoria
Unequal pupil size.
Miosis
Abnormally small pupils.
Mydriasis
Abnormally dilated pupils.
Fixed Pupil
A pupil that shows little or no reaction to light.
Non-reactive Pupil
A pupil that does not show the expected response to light.
A new abnormal pupil finding, especially when associated with altered consciousness, severe headache, weakness, trauma or other neurological signs, requires prompt clinical assessment and escalation according to emergency protocol.
Pupillary Assessment Procedure
- Explain the procedure.
- Assess pupil size in both eyes.
- Compare symmetry.
- Observe pupil shape.
- Assess response to light.
- Compare direct and consensual responses.
- Assess accommodation when indicated.
- Document findings.
- Compare with previous neurological observations.
Normal Adult Vital Signs – Quick Reference
| Parameter | Common Adult Reference |
|---|---|
| Temperature | Approximately 36.1–37.2°C commonly; varies with method/person |
| Pulse | 60–100 bpm |
| Respiration | Approximately 12–20 breaths/minute |
| Blood Pressure | Normal category: <120/<80 mmHg |
| SpO₂ | Target depends on clinical condition |
| Pain | 0 = no pain; 10 = worst imaginable pain on a 0–10 scale |
| Pupils | Normally assessed for size, symmetry, shape and light reaction |
Reference ranges may differ according to age, clinical setting, measurement method and patient condition. Always use the appropriate age-specific or condition-specific reference when assessing a patient.
Factors Affecting Vital Signs
Physiological Factors
- Age
- Exercise
- Sleep
- Pregnancy
- Circadian rhythm
Psychological Factors
- Anxiety
- Fear
- Stress
- Excitement
- Pain
Pathological Factors
- Infection
- Hemorrhage
- Shock
- Respiratory disease
- Cardiac disease
- Neurological disorders
- Endocrine disorders
Medication Factors
- Beta blockers
- Opioids
- Antipyretics
- Antihypertensives
- Sedatives
- Bronchodilators
Clinical Assessment Sequence – Most Important Section
The sequence of assessment depends on whether the patient is stable or unstable.
Routine Stable Patient
This sequence may be modified according to institutional protocol and the patient's condition.
Unstable or Emergency Patient
In an unstable patient, do not simply follow the textbook order of temperature → pulse → respiration → BP. ABCDE assessment takes priority.
Reassessment Sequence
Assessment Sequence in Different Clinical Situations
1. Routine Stable Patient
Sequence:
General appearance → Temperature → Pulse → Respiration → BP → SpO₂ → Pain → Focused assessment → Documentation
2. Emergency / Critically Ill Patient
Sequence:
ABCDE → Vital signs → Focused assessment → Monitoring → Intervention → Reassessment
3. Unconscious Patient
Sequence:
Airway → Breathing → Circulation → Level of consciousness/GCS or AVPU → Pupils → Blood glucose when indicated → Full vital signs → Focused neurological assessment
4. Patient With Respiratory Distress
Sequence:
Airway → Breathing → Respiratory rate → SpO₂ → Work of breathing → Chest assessment → Pulse → BP → Mental status → Reassessment
5. Suspected Shock
Sequence:
ABCDE → Pulse → BP/MAP → Respiratory rate → SpO₂ → Mental status → Skin/perfusion → Capillary refill → Urine output → Reassessment
6. Chest Pain
Sequence:
ABCDE → Pain assessment using OPQRST/PQRST → Pulse/heart rate → BP → SpO₂ → Cardiac assessment → ECG as indicated → Reassessment
7. Neurological Emergency
Sequence:
ABCDE → Level of consciousness → GCS/AVPU → Pupils → Motor/sensory assessment → BP → Pulse → Respiration → SpO₂ → Blood glucose when indicated → Focused neurological assessment
8. Fever / Suspected Infection
Sequence:
General appearance → Temperature → Pulse → Respiratory rate → BP → SpO₂ → Hydration/perfusion → Infection-focused assessment → Mental status → Reassessment
9. Post-Operative Patient
Sequence:
Airway → Breathing → SpO₂ → Respiratory rate → Circulation → Pulse → BP → Level of consciousness → Pain → Surgical site/drains → Urine output → Reassessment
10. Severe Pain
Sequence:
Initial safety assessment/ABCDE when indicated → Pain assessment → Vital signs → Focused examination → Intervention → Reassessment
11. Trauma / Fall Patient
Sequence:
ABCDE → Cervical spine precautions when indicated → Level of consciousness → Pupils → Vital signs → Head-to-toe assessment → Pain → Reassessment
12. Pediatric Patient
Sequence:
General appearance → Airway → Breathing/RR → SpO₂ → HR/Pulse → Perfusion → BP when appropriate → Temperature → Pain → Neurological assessment
Pediatric vital-sign ranges are age-dependent. Adult reference values should not be applied to children.
13. Suspected Sepsis
Sequence:
ABCDE → Temperature → HR → RR → BP/MAP → SpO₂ → Mental status → Perfusion → Urine output → Sepsis pathway and investigations according to local protocol → Frequent reassessment
14. Before Medication Administration
Sequence:
Patient identification → Relevant history/allergies → Baseline assessment → Vital signs required for the medication → Administer medication → Monitor response/adverse effects → Reassessment → Documentation
15. Patient Receiving Oxygen Therapy
Sequence:
Airway → Respiratory effort → RR → SpO₂ → Oxygen device and flow → Lung assessment → Pulse → BP → Mental status → Response to oxygen therapy → Documentation
16. Altered Mental Status
Sequence:
ABCDE → Level of consciousness → Pupils → Blood glucose when indicated → Vital signs → Neurological assessment → Medication/toxin history → Focused assessment → Reassessment
Nursing Responsibilities During Vital Sign Assessment
- Identify the patient correctly.
- Explain the procedure.
- Perform hand hygiene.
- Use appropriate equipment.
- Ensure proper patient positioning.
- Use correct measurement technique.
- Assess the patient's general appearance.
- Compare findings with previous values.
- Repeat questionable or abnormal measurements when clinically appropriate.
- Recognize significant changes.
- Report serious abnormalities promptly.
- Document findings accurately.
- Continue monitoring according to the patient's condition.
Documentation of Vital Signs
Documentation should be accurate, timely and complete.
- Date
- Time
- Temperature and site/method when relevant
- Pulse rate and rhythm
- Respiratory rate and characteristics
- Blood pressure
- SpO₂
- Oxygen device/flow when applicable
- Pain score and assessment scale
- Pupillary findings when neurological assessment is indicated
- Relevant symptoms
- Interventions and patient response when appropriate
Example
T 37.2°C, PR 84/min regular, RR 18/min, BP 118/76 mmHg, SpO₂ 98% on room air, pain 2/10. Patient conscious and comfortable. Pupils equal and reactive to light.
Important Current Clinical Points
1. Correct Blood Pressure Technique Matters
Accurate BP measurement requires appropriate cuff size, correct positioning and standardized technique. Incorrect measurement can result in inappropriate clinical decisions.
2. SpO₂ Is Commonly Used in Modern Patient Monitoring
Pulse oximetry is routinely used in many emergency, ward, perioperative and critical-care settings.
3. SpO₂ Targets Are Patient-Specific
Oxygen saturation should be interpreted according to the patient's underlying condition and prescribed target rather than using one universal target for every patient.
4. Trends Matter
A progressive change may be more clinically important than a single abnormal value.
If this trend is accompanied by tachycardia, reduced urine output, confusion or other signs of poor perfusion, urgent clinical assessment is required.
5. ABCDE Comes First in the Unstable Patient
The patient's immediate threats to life should be identified and managed before completing routine observations.
High-Yield Nursing Exam Revision
- Traditional vital signs: Temperature, Pulse, Respiration and Blood Pressure.
- Normal adult pulse: 60–100 bpm.
- Common adult respiratory reference: 12–20/min.
- Average body temperature: approximately 37°C.
- Normal BP category: <120/<80 mmHg.
- Pulse pressure: SBP − DBP.
- MAP: DBP + 1/3 pulse pressure.
- Tachycardia: resting adult HR >100 bpm.
- Bradycardia: resting adult HR <60 bpm.
- SpO₂: measured using pulse oximetry.
- PERRLA: Pupils Equal, Round, Reactive to Light and Accommodation.
- Direct reflex: illuminated pupil constricts.
- Consensual reflex: opposite pupil constricts.
- Anisocoria: unequal pupils.
- Miosis: constricted pupils.
- Mydriasis: dilated pupils.
- Emergency priority: ABCDE.
- Pain assessment: PQRST/OPQRST.
Frequently Asked Questions About Vital Signs
Temperature, pulse, respiration and blood pressure.
The commonly used resting adult range is 60–100 beats per minute.
A commonly taught adult resting range is approximately 12–20 breaths per minute.
Approximately 37°C is traditionally considered the average, although normal temperature varies with individual and measurement conditions.
It is the arterial pressure during ventricular contraction and is the upper number of a BP reading.
It is the arterial pressure during ventricular relaxation and is the lower number of a BP reading.
Pulse pressure is calculated as systolic BP minus diastolic BP.
MAP means Mean Arterial Pressure and can be estimated using DBP + 1/3(SBP − DBP).
SpO₂ is an estimate of peripheral oxygen saturation measured using a pulse oximeter.
PERRLA stands for Pupils Equal, Round, Reactive to Light and Accommodation.
Anisocoria means unequal pupil size.
Pain is traditionally called the fifth vital sign in nursing education.
The priority is ABCDE: Airway, Breathing, Circulation, Disability and Exposure.
An inappropriate cuff size can contribute to inaccurate blood pressure readings.
Trends can reveal progressive deterioration even when an individual value does not appear severely abnormal.
10 MCQs on Complete Vital Signs
1. Which of the following is a traditional vital sign?
A. Blood glucose
B. Temperature
C. Height
D. Weight
2. What is the commonly accepted resting pulse range for an adult?
A. 20–40 bpm
B. 40–50 bpm
C. 60–100 bpm
D. 120–160 bpm
3. A respiratory rate of 8 breaths/minute in an adult is called:
A. Eupnea
B. Tachypnea
C. Bradypnea
D. Hyperpnea
4. A BP reading is 120/80 mmHg. What is the pulse pressure?
A. 20 mmHg
B. 30 mmHg
C. 40 mmHg
D. 80 mmHg
5. Which device is used to measure SpO₂?
A. Thermometer
B. Sphygmomanometer
C. Pulse oximeter
D. Glucometer
6. What does PERRLA refer to?
A. Blood pressure assessment
B. Pupillary assessment
C. Respiratory assessment
D. Pain assessment
7. Unequal pupil size is called:
A. Miosis
B. Mydriasis
C. Anisocoria
D. Diplopia
8. What is the priority assessment sequence for an unstable patient?
A. Temperature → Pulse → Respiration → BP
B. Pain → Temperature → BP → Pulse
C. ABCDE
D. Weight → Height → BMI
9. Which method is appropriate for assessing pain characteristics?
A. PQRST
B. ABCDE only
C. PERRLA
D. Glasgow only
10. Which finding should receive urgent neurological attention when it is new and associated with altered consciousness?
A. Equal reactive pupils
B. Normal temperature
C. New fixed or non-reactive pupil
D. Regular radial pulse
Answers and Explanations
| Question | Answer | Explanation |
|---|---|---|
| 1 | B. Temperature | Temperature is one of the traditional four vital signs. |
| 2 | C. 60–100 bpm | This is the commonly used resting adult pulse range. |
| 3 | C. Bradypnea | Bradypnea means abnormally slow breathing. |
| 4 | C. 40 mmHg | Pulse pressure = 120 − 80 = 40 mmHg. |
| 5 | C. Pulse oximeter | SpO₂ is estimated using pulse oximetry. |
| 6 | B. Pupillary assessment | PERRLA is used to describe pupil size, shape and response. |
| 7 | C. Anisocoria | Anisocoria means unequal pupil size. |
| 8 | C. ABCDE | Airway, Breathing, Circulation, Disability and Exposure are the priority sequence for unstable patients. |
| 9 | A. PQRST | PQRST helps assess the characteristics, severity and timing of pain. |
| 10 | C. New fixed or non-reactive pupil | A new abnormal pupil finding with altered consciousness can indicate serious neurological deterioration and requires urgent assessment. |
Complete Vital Signs – One-Minute Revision
Temperature → Body heat / thermoregulation
Pulse → Heart rate, rhythm and peripheral perfusion
Respiration → Rate, rhythm, depth and effort
Blood Pressure → Systolic + Diastolic pressure
SpO₂ → Oxygen saturation assessment
Pain → PQRST / OPQRST
Pupils → Size + Shape + Symmetry + Light reaction + Accommodation
Unstable patient → ABCDE
Final Clinical Message for Nursing Students
Vital signs are not merely numbers recorded on a chart. They are important clinical clues that help nurses recognize changes in a patient's physiological condition.
A competent nurse should know the normal ranges, but professional nursing assessment requires much more: correct technique, recognition of abnormal findings, comparison with baseline, interpretation of trends and timely escalation.
In an unstable patient, remember:
Then perform the appropriate focused assessment, monitor vital signs, intervene according to the clinical situation and reassess the patient.
“Assess the patient, not just the number.”
This article is prepared for nursing education and examination purposes. Vital-sign reference ranges and clinical targets may vary according to age, patient condition, measurement method, institutional protocol and current clinical guidelines. In actual patient care, follow the applicable hospital protocol and instructions of the responsible healthcare team.