Knowing how to perform cardiopulmonary resuscitation (CPR) could help save someone’s life during a medical emergency. CPR is an emergency procedure used when a person becomes unresponsive and is not breathing normally, or is only gasping for air.

The procedure helps maintain blood flow to the brain and other vital organs while emergency medical assistance is on the way. Although CPR training is recommended, members of the public can help during a suspected cardiac arrest by recognising the emergency, calling for help and starting chest compressions.

Here are the steps to follow when performing CPR on an adult.

Step 1: Check the person’s condition

Before helping, make sure the area is safe. Tap the person on the shoulders and speak loudly to check whether they respond.

If the person does not respond, check whether they are breathing normally. Do not mistake occasional gasps, irregular snorting or abnormal breathing for normal breathing.

Step 2: Call for emergency help

If the person is unresponsive and is not breathing normally, call the local emergency number or direct someone nearby to contact emergency services immediately.

Ask another person to find an automated external defibrillator (AED), if one is available. Put your phone on speaker mode so you can follow the emergency operator’s instructions while helping the person.

Step 3: Position your hands correctly

Lay the person flat on their back on a firm, level surface.

Kneel beside the person’s chest and place the heel of one hand in the centre of the chest, on the lower half of the breastbone. Place your other hand on top and interlock your fingers.

Keep your arms straight and position your shoulders directly above your hands.

Step 4: Begin chest compressions

Push hard and fast in the centre of the chest.

For an adult, compress the chest to a depth of at least 5 centimetres, or about 2 inches, at a rate of 100 to 120 compressions per minute.

Allow the chest to return to its normal position after each compression. Avoid leaning on the chest between compressions, and minimise interruptions.

Step 5: Continue CPR and use an AED if available

If you are not trained in CPR or are unwilling to give rescue breaths, continue hands-only CPR by performing chest compressions until emergency responders arrive, the person shows clear signs of life, the scene becomes unsafe, or you are physically unable to continue.

If you are trained and able to give rescue breaths, use the standard adult CPR cycle of 30 chest compressions followed by two rescue breaths.

When an AED arrives, switch it on and follow its voice instructions. Attach the pads as directed, make sure nobody touches the person while the device analyses the heart rhythm or delivers a shock, and resume CPR immediately when instructed.

Important safety information

CPR techniques differ for adults, children and infants. The compression depth, hand position and rescue-breathing approach may vary depending on the person’s age and circumstances.

Do not delay chest compressions while trying to find the perfect position or waiting for an AED. If you are unsure what to do, call emergency services and follow the operator’s instructions.

CPR does not guarantee survival, but starting it promptly can improve the person’s chance of survival during cardiac arrest. Learning the procedure through a recognised first-aid course can help you respond more confidently when an emergency occurs.