Why this matters: A first aider often has only a few minutes to recognise deterioration, control catastrophic bleeding and communicate useful observations. Vital signs are not isolated numbers; they are trends that show whether the heart, brain and tissues are being perfused.
Add an image showing a first aider assessing pulse, breathing, blood pressure and skin colour here.
Learning outcomes
- Explain the purpose and limitations of first-aid vital-sign assessment.
- Perform a safe primary survey and obtain a reliable pulse, respiratory rate, temperature, blood pressure and oxygen-saturation reading when equipment is available.
- Locate major pulse and haemorrhage-control pressure points without causing additional injury.
- Recognise shock, poor perfusion, acute coronary syndrome and other cardiovascular emergencies requiring urgent referral.
- Document findings as time-stamped trends and communicate them using a structured handover.
1. First aid assessment begins with safety
Before touching the casualty, pause and scan for traffic, fire, electricity, violence, chemicals, unstable structures, blood or body-fluid exposure and other casualties. Wear gloves or improvise a barrier if blood is present. Do not become a second casualty. Introduce yourself, obtain consent from a responsive person and ask someone to call the local emergency service or bring an emergency kit.
DRABC: Danger – make the scene safe; Response – speak and gently tap the shoulder; Airway – open and inspect; Breathing – look, listen and feel for normal breathing for up to 10 seconds; Circulation/Catastrophic bleeding – control life-threatening bleeding and start CPR when indicated.
Life-threatening bleeding and absent or abnormal breathing take priority over a complete set of vital signs. A blood-pressure reading must never delay CPR, defibrillation, airway opening or haemorrhage control.
2. What the vital signs tell you
| Observation | What it reflects | How to interpret it in first aid |
|---|---|---|
| Respiratory rate and effort | Ventilation and work of breathing | Fast, slow, irregular, noisy or laboured breathing may indicate shock, airway obstruction, asthma, chest injury, poisoning or cardiac arrest. |
| Pulse rate, rhythm and quality | Heart rate and peripheral perfusion | A weak, very fast, irregular or absent pulse is concerning; compare both sides only when injury is not suspected. |
| Blood pressure | Pressure generated by the circulating blood | A falling pressure with confusion, cold skin or a rapid pulse suggests decompensating shock, but a single normal reading does not exclude serious injury. |
| Temperature | Thermal balance and infection/environmental stress | High temperature may accompany infection or heat illness; low temperature may accompany exposure, shock, sepsis or hypoglycaemia. |
| SpO₂, when available | Estimated arterial oxygen saturation | Read alongside the patient’s appearance and breathing; cold fingers, movement, nail products and poor circulation can produce misleading values. |
| Level of consciousness | Brain perfusion, oxygenation and neurological function | Use AVPU and note new confusion, drowsiness, agitation or inability to answer normally. |
| Skin and capillary refill | Peripheral perfusion and temperature regulation | Pale, grey, blue, clammy or mottled skin, delayed refill and sweating are warning signs, especially with collapse or bleeding. |
3. Measuring vital signs correctly
Respiratory rate
- Keep the person resting and, if possible, count without announcing that you are counting breaths because conscious control can change the rate.
- Watch the chest or abdomen for a complete minute when rhythm is irregular; otherwise count for 30 seconds and multiply by two.
- Record rate, rhythm, depth, effort, sounds, colour and ability to speak. Note accessory-muscle use, nasal flaring, grunting, wheeze, stridor or gasping.
- Gasping is not normal breathing. Activate emergency help and begin CPR if the person is unresponsive and not breathing normally.
Pulse
- Use the pads of the index and middle fingers, never the thumb. Count for 30–60 seconds and describe rate, rhythm, volume and symmetry.
- Use the radial pulse in a stable adult. Use the carotid or femoral pulse for an unresponsive adult when trained, checking one side only at a time.
- A pulse that is rapid and weak may indicate blood loss or shock; an irregular pulse may indicate dysrhythmia. Do not diagnose the rhythm from palpation alone.
Blood pressure
- Seat or lay the person quietly with the arm supported at heart level. Use the correct cuff: a cuff that is too small falsely raises the reading.
- Do not use an injured, paralysed, fistula or intravenous-infusion limb when another limb is safe. Avoid taking a cuff reading over clothing.
- Record the systolic/diastolic result, arm, position, cuff type, time and symptoms. Repeat an unexpected result after rest if the emergency does not require immediate transport.
- In trauma, a normal pressure can be maintained until significant blood loss has occurred. Treat the person, not the number.
Temperature, oxygen saturation and AVPU
Use the method and site recommended by the device manufacturer. Document whether the temperature is oral, axillary, tympanic or temporal. With a pulse oximeter, warm the hand, remove motion and check the waveform or signal quality. AVPU means Alert, responds to Voice, responds to Pain and Unresponsive; any deterioration requires escalation.
4. Normal adult reference ranges and red flags
| Measure | Common resting adult reference | Red flags in first aid |
|---|---|---|
| Pulse | Approximately 60–100 beats/minute | Absent, very fast, very slow, irregular with collapse, or weak and thready. |
| Respirations | Approximately 12–20 breaths/minute | Gasping, pauses, severe effort, cyanosis, inability to speak, stridor or rapidly increasing rate. |
| Blood pressure | Varies with age, health and context | Low or falling pressure with shock signs; severe hypertension with chest pain, neurological deficit or severe headache. |
| Temperature | Roughly 36–37.5°C, depending on site | Very high temperature with altered mental state; low temperature with confusion, drowsiness or exposure. |
| SpO₂ | Usually 95–100% at sea level in a healthy adult | Persistently low reading, falling trend, or any low reading with respiratory distress; interpret in context and follow local protocol. |
These are teaching ranges, not diagnostic cut-offs. Children, pregnancy, athletes, altitude, chronic lung disease, medicines and anxiety alter normal values. Trend the observations and seek professional help when the person looks seriously ill.
5. Pulse points and pressure points
A pulse point is where an artery can be felt. A pressure point is a proximal artery that may be compressed against a firm underlying structure to temporarily reduce flow. Modern first aid controls bleeding first with direct pressure, wound packing and an appropriate tourniquet. Pressure points are an emergency adjunct only and must never replace direct pressure or delay transport.
| Site | How to locate it | Use and safety note |
|---|---|---|
| Radial | Thumb side of the wrist, just proximal to the base of the thumb | Routine adult pulse. Do not rely on it in profound shock or a wrist injury. |
| Carotid | Groove beside the trachea, between the windpipe and sternocleidomastoid | Use gently and on one side only. Never massage or compress both carotids. |
| Brachial | Medial upper arm or antecubital fossa | Useful in infants and when assessing an upper-arm injury; avoid an injured limb. |
| Femoral | Midpoint of the groin crease | Central pulse in collapse; direct deep pressure can injure structures and is for trained responders. |
| Popliteal | Deep in the hollow behind the knee | Assesses lower-limb circulation; difficult to locate and not a routine bleeding-control method. |
| Posterior tibial | Behind and slightly below the medial ankle bone | Distal foot perfusion. |
| Dorsalis pedis | Top of the foot, usually lateral to the tendon of the great toe | Compare sides when safe; anatomical variation is common. |
| Temporal/facial | Temple or lower jaw border | May help identify facial circulation but facial wounds usually require direct pressure and urgent assessment. |
| Subclavian/axillary | Above the clavicle or high in the axilla | Deep, difficult and potentially dangerous. Do not compress the neck or chest in an untrained attempt. |
6. Cardiovascular assessment in the first-aid setting
- General appearance: note pallor, sweating, cyanosis, agitation, collapse, fatigue and the ability to speak.
- Chest symptoms: ask about pressure, tightness, heaviness, pain radiating to the arm, jaw or back, breathlessness, nausea and a sense of impending doom.
- Circulation: check pulse, skin temperature, capillary refill, major bleeding, limb colour and symmetry. Look for swelling, obvious deformity or a cold limb.
- Perfusion: compare mental state, pulse quality and skin findings. A deteriorating person may become anxious, thirsty, pale and clammy before losing consciousness.
- History: use SAMPLE—Symptoms, Allergies, Medications, Past history, Last oral intake and Events—without delaying lifesaving care.
Chest-pain emergency: stop exertion, sit the person in a comfortable position, call emergency help, monitor breathing and consciousness, and follow dispatcher/local protocol. Do not allow the person to walk to a facility. Be ready to start CPR if they become unresponsive and stop breathing normally.
7. Documentation and handover
| Record | Example |
|---|---|
| Time and context | 14:20, collapsed after walking in the sun; no obvious trauma. |
| Initial state | Responds to voice; airway open; breathing fast but present. |
| Observations | Pulse 118/min, weak; RR 28/min; BP 94/60 mmHg; skin pale/clammy. |
| Action and response | Laid safely, bleeding controlled, ambulance called; observations repeated after 5 minutes. |
Use an ATMIST or SBAR-style handover: Age, Time of incident, Mechanism/medical complaint, Injuries/observations, Signs and Treatment given. State changes rather than only the latest number.
8. Practical scenario
Scenario: A 52-year-old man becomes pale and sweaty while carrying a heavy load. He reports central chest pressure and nausea. His radial pulse is rapid. Response: stop exertion, keep him at rest in a comfortable position, activate emergency transport, gather his medication/allergy history, monitor airway and breathing, and prepare for CPR/AED if he collapses. Do not give food or drink and do not send him walking to the clinic.
Exam points and revision questions
- Explain why direct pressure is preferred to pressure points for severe external bleeding.
- Describe how to count an irregular respiratory rate and document the result.
- List five signs of poor cardiovascular perfusion.
- Demonstrate radial and carotid pulse assessment while stating the safety precautions.
- Explain why a single normal blood-pressure result cannot exclude shock.