Holding your breath is an example of apnea, as is sleep apnea, a condition where a person stops breathing repeatedly while sleeping.
In very sick patients, an apnea test may be performed to determine if the patient is able to breathe on their own, or if they are apneic and require a ventilator to breathe.
During surgery, a patient is apneic because of the anesthesia drugs given that paralyze the respiratory system. For that reason, patients receiving general anesthesia will be on a ventilator during the procedure.


