Stay calm and assess the situation quickly

Choking is one of the most frightening things you can witness at home, but it is also one of the situations where a calm, confident response makes the biggest difference. The right action depends on one simple question: is the airway partly blocked, or completely blocked? Ask the person, "Are you choking?" If they can answer you, cough, or breathe, the airway is only partly blocked. If they cannot make a sound, cough, or breathe, treat it as severe choking and act immediately.

Shout for help, and if there is anyone else nearby, ask them to call 999 (or 112) while you begin. If you are alone with the person, start helping first and call once you can.

Mild choking: encourage coughing

A forceful cough is the most effective way to shift an obstruction, so if the person is coughing well, your job is to support them rather than take over.

• Encourage them to keep coughing and to spit out anything that comes up.
• Stay with them, keep them upright, and reassure them calmly.
• Do not slap their back while they are coughing effectively, as this can move the object.
• Do not put your fingers into their mouth unless you can clearly see the object and can reach it safely.

Watch closely. If the cough becomes weak or silent, or they stop being able to speak or breathe, move straight on to the steps below.

Severe choking: back blows, then abdominal thrusts

For an adult or a child over one year, use the sequence of five back blows followed by five abdominal thrusts, repeating until the obstruction clears or help arrives.

Back blows. Stand to the side and slightly behind them. Support their chest with one hand, lean them forward so their head is lower than their chest, and give up to five sharp blows with the heel of your hand between the shoulder blades. Check after each blow whether the object has come out.

Abdominal thrusts. If the back blows have not worked, stand behind them with your arms around their waist. Lean them forward, make a fist, and place it just above the navel — well below the breastbone. Grasp your fist with your other hand and pull sharply inwards and upwards up to five times. Check their mouth after each thrust and remove anything you can clearly see.

Keep alternating five back blows and five abdominal thrusts. If you have not already called 999, do so now — the ambulance crew can talk you through what to do while they are on the way.

Babies and young children

Children over one can be treated with the same back blows and abdominal thrusts as adults, but kneel or bend down to their level. For a small child, you may find it easier to use one hand instead of two for the thrusts.

Babies under one year need a different technique, and abdominal thrusts must never be used on them.

• Five back blows: lay the baby face down along your forearm, resting on your thigh, with the head lower than the chest. Support the jaw with your fingers and give up to five firm blows between the shoulder blades with the heel of your hand.
• Five chest thrusts: turn the baby face up, still with the head lower than the body. Place two fingers on the lower half of the breastbone, roughly one finger's width below the nipple line, and press down firmly about a third of the depth of the chest, five times.
• Alternate five back blows and five chest thrusts, calling 999 as soon as you can.

If they become unresponsive

If the person stops responding, lay them gently on the floor, open their airway by tilting the head back and lifting the chin, and check for normal breathing for up to ten seconds. If they are not breathing normally, begin CPR — 30 chest compressions followed by two rescue breaths, and continue. If you are unable or unwilling to give rescue breaths, do compressions only, pushing hard and fast in the centre of the chest. Ask someone to fetch the nearest defibrillator if there is one nearby, and follow the instructions from the 999 call handler.

Even when the obstruction clears, anyone who received abdominal or chest thrusts should be seen by a medical professional, as these manoeuvres can cause internal bruising. If the object was never coughed out but the person seems fine, it is still worth seeking advice, because a fragment may remain in the airway.

Preventing choking at home

Most choking incidents are preventable, especially where young children are involved. Keep these habits in mind:

• Cut food into small pieces for children — quarter grapes and cherry tomatoes lengthways, and chop sausages and carrots into strips rather than rounds.
• Avoid whole nuts, hard sweets, popcorn, and marshmallows for children under four.
• Sit children down to eat and supervise them — eating while walking, running, or lying down raises the risk.
• Keep small objects such as coins, buttons, and pen lids out of reach of babies and toddlers.
• Chew food properly, and take extra care with dry or stringy foods like steak, bread, and peanut butter.

It is also worth learning hands-on CPR and choking skills through a local first aid course, and keeping a note of your nearest public defibrillator. A few minutes of practice now can turn a terrifying moment into one you can handle with confidence.