Choking occurs when an object becomes stuck in the throat or the windpipe and blocks air from flowing into the lungs.
Children, particularly those under five, often put objects in their mouth. This is a normal part of how they explore the world. However, some small objects or food items can be just the right size to get stuck in a child's airway and cause choking.
https://www.nidirect.gov.uk/articles/choking
