The 5 Steps of Basic Life Support Explained

A colleague collapses in a staff room. A visitor becomes unresponsive at reception. In these moments, the 5 steps of basic life support give your team a clear, practical sequence to follow before professional help arrives. Knowing what to do protects your people, supports a faster emergency response and can save a life.

Basic Life Support, often called BLS, is not about complicated clinical procedures. It is about recognising a life-threatening emergency, calling for help without delay and giving effective CPR and AED treatment where needed. For employers, schools, care settings and community organisations, these are skills that must work under pressure, not just look correct on a certificate.

The 5 steps of basic life support

The exact approach should always reflect current recognised guidance and the needs of the casualty. However, for an adult who has collapsed, the following five steps provide a dependable framework for action.

1. Check that it is safe to help

Before approaching, look for immediate dangers to yourself, the casualty and other people nearby. This could include traffic, live electrical equipment, fire, unsafe machinery, violence, spilled chemicals or broken glass. A rescuer becoming injured creates another casualty and delays help.

If the area is unsafe, do not put yourself at risk. Move away, raise the alarm and wait for emergency services where necessary. If it is safe to approach, introduce yourself if appropriate and begin your assessment.

In a workplace, this step should be grounded in the hazards your staff genuinely face. A warehouse, school science room, care home, construction site and office reception all present different risks. Effective first aid training helps people make that judgement quickly rather than following a script without thinking.

2. Check for a response

Speak loudly and clearly to the person. Ask a simple question, such as, “Can you hear me?” Gently tap their shoulders. Do not shake them or cause unnecessary movement, particularly if a fall, collision or spinal injury may have occurred.

If they respond, leave them in the position in which you found them unless there is danger. Check what has happened, look for signs of injury or illness and summon help if needed. Continue to monitor them because a casualty’s condition can deteriorate quickly.

If there is no response, treat the situation as urgent. Shout for help from anyone close by. In a busy organisation, staff should understand who takes control of the immediate response, who calls 999, who retrieves the AED and who manages other pupils, residents, customers or colleagues. Clear roles prevent precious seconds being lost to confusion.

3. Call 999 and send for an AED

If the casualty is not breathing normally, call 999 immediately. Put your phone on speaker so that you can follow instructions while staying with the casualty. If someone else is present, direct them clearly: “Call 999 now. Tell them we have an unresponsive adult who is not breathing normally. Bring the AED.”

An automated external defibrillator, or AED, is designed to be used by trained and untrained people. It gives spoken instructions, analyses the heart rhythm and will only advise a shock when appropriate. Early defibrillation can be critical in a cardiac arrest, so staff need to know where the nearest device is kept and how to access it outside normal hours.

This is one area where planning matters as much as training. An AED locked in an office, hidden in a cupboard or unknown to new starters cannot help when it is needed. Include the device in inductions, emergency procedures and routine equipment checks.

4. Open the airway and check breathing

An unresponsive person may have an obstructed airway because their tongue has fallen back. Carefully open their airway using a head tilt and chin lift: place one hand on their forehead, tilt the head back gently and lift the chin with two fingers. If you can see an obvious obstruction in the mouth, remove it only if it is easy to do so. Do not sweep blindly with your fingers.

Look, listen and feel for normal breathing for no more than 10 seconds. Look for chest movement, listen for breath sounds and feel for air on your cheek. Occasional gasps, snorts or irregular breathing are not normal breathing. These agonal breaths can happen in cardiac arrest and must not be mistaken for recovery.

If the person is breathing normally but remains unresponsive, place them in the recovery position where it is safe and appropriate, call 999 and keep checking their breathing. If you suspect a serious injury, minimise movement where possible, but airway and breathing problems always take priority.

5. Start CPR and use the AED as soon as it arrives

Begin chest compressions without delay. Place the heel of one hand in the centre of the chest, place your other hand on top and interlock your fingers. Keep your arms straight and press down 5 to 6 cm at a rate of 100 to 120 compressions per minute. Allow the chest to fully rise between compressions.

If you are trained and willing to give rescue breaths, provide 30 chest compressions followed by two breaths. Maintain a 30:2 ratio. If you cannot give breaths, or do not feel able to, deliver continuous chest compressions. High-quality compressions are far better than delaying because you are uncertain.

As soon as the AED arrives, switch it on and follow its voice prompts. Expose the chest, attach the pads as shown on the diagrams and make sure nobody is touching the casualty while the AED is analysing or delivering a shock. Resume CPR immediately when instructed. Continue until the casualty shows clear signs of life, emergency services take over or you are physically unable to continue.

Why organisations need practical BLS training

A written procedure is necessary, but it cannot prepare someone for the physical reality of an emergency. Staff need to practise kneeling beside a casualty, locating hand position, achieving the right compression depth and rhythm, applying AED pads and communicating with others in the room. Confidence comes from repetition and expert feedback.

There is also a compliance consideration. UK employers must make suitable first aid arrangements based on an assessment of workplace risks. The right provision depends on factors such as staff numbers, shift patterns, public access, known health risks, remote working, distance from emergency services and the age or vulnerability of people in your care. One size does not fit every workplace.

Basic Life Support training can be particularly valuable for teams in schools, nurseries, care homes, healthcare environments, leisure venues and public-facing sites. These organisations may need staff to act before a designated first aider reaches the scene. Paediatric emergencies require different considerations, so teams responsible for babies and children should receive training that specifically covers their setting.

Refresher practice matters too. Skills can fade when they are not used, and CPR guidance, equipment and workplace arrangements can change. Regular training helps staff retain the ability to act decisively rather than relying on vague memories from a course taken years earlier.

Build a response your team can use

The strongest emergency plans are simple, rehearsed and visible. Make sure your team knows the location of first aid kits and AEDs, how to contact emergency services from the site, the site address or postcode, and who will meet an ambulance on arrival. Record incidents properly afterwards and offer support to anyone involved, as responding to a serious emergency can be distressing.

Training 2 U delivers hands-on Basic Life Support training at workplaces across Merseyside, Lancashire, Cheshire and Greater Manchester, led by instructors with more than three decades of frontline clinical experience. The aim is straightforward: help your people recognise the emergency, take the right action and keep going until help arrives.

When a life is at risk, staff do not need perfect words or medical jargon. They need a calm sequence, practical skill and the confidence to start. Give them the preparation to act.