Why Legislators and Doctors Don’t Always Agree on the Definition of Death

While Patients' Families Think Life Ends With Your Last Breath, 50 States Point to Brain Activity

How can you truly know when someone is dead? Historically, death was determined by holding a mirror up to a person’s mouth to see if they were breathing. But this method was not foolproof, so safety coffins outfitted with a string attached to a bell were used to allow someone who woke up after burial to easily send out a distress signal.

Today, the most commonly accepted definition of death is irreversible cardiopulmonary arrest—when a person no longer has a palpable pulse, an audible heartbeat, or sounds of breathing. …