Philadelphia Fire Department Practice Exam

According to medical experts, how many minutes without oxygen could result in brain damage?

1. Two

2. Three

3. Four

4. Five

The correct answer is: Four

The benchmark often cited by medical experts is that brain cells begin to suffer damage after approximately four minutes without oxygen. This is due to the brain's high sensitivity to oxygen deprivation, as it requires a constant supply to function properly. After four minutes, the likelihood of irreversible brain damage increases significantly, leading to the risk of long-term neurological impairment. If oxygen deprivation continues beyond this timeframe, the potential for brain injury escalates. Although some brain cells may begin to deteriorate sooner, the four-minute mark is widely recognized as critical for initial interventions and resuscitative efforts. Understanding this timeframe is fundamental for emergency medical responders, allowing them to prioritize timely intervention when faced with situations such as cardiac arrest or drowning, where oxygen supply may be compromised.