Although children's hearing aids have battery compartments that are allegedly childproof, these compartments can still fail or break, or a young child could figure out how to open the battery compartment. If batteries are not properly stored or discarded away from a young child's reach, the child could swallow them.
Dangers of Swallowing Hearing Aid Batteries
Swallowed batteries can tear or burn the throat (esophagus). If the battery has poisoned the child, there may be pain, vomiting or bleeding. The airway can be obstructed, organs can be damaged by poisoning, and in rare cases, death can occur.
What to Do If a Hearing Aid Battery Is Swallowed
The National Capital Poison Center has a page with advice on battery swallowing. Swallowing a hearing aid battery means an immediate trip to the emergency room for an x-ray to find where the battery is in the body. Depending on the location of the battery in the body, either the battery will have to be removed right away or parents can wait for the battery to pass out of the body.