Choking is defined as an obstruction of the upper part of the windpipe (trachea) resulting in an acute life-threatening emergency (Figure 8.4). A person whose airway is obstructed will quickly become unconscious and die due to suffocation (lack of oxygen), unless the obstruction is quickly removed. Look back at Figure 4.1 in Study Session 4 of this Module to remind yourself of the location of the trachea in the respiratory system.

Figure 8.4 Food obstructing the airway is the commonest cause of choking.

An obstruction of the airway may be partial or complete, and choking may occur in the conscious or unconscious person. The common causes of choking that you may be faced with are:

Blockage of the airway by the tongue falling back into the throat of an unconscious person who is lying on their back (see Figure 8.4(a) later in this study session)
Inhalation (breathing in) of a piece of food, such as a lump of meat, a chicken or fish bone, a bean or a nut; children may also inhale small objects during play
Injury to the airway, for example after a blow to the front of the neck.