Being brain dead means a complete and permanent loss of brain function. It is not the same as being in a coma or vegetative state. Diagnosis involves thorough testing and observation. Once confirmed, there is no possibility of recovery. While this is a painful reality for loved ones, it can also offer a chance to give life to others through organ donation.
Brain death is a medical and legal definition of death. It means that a person’s brain has permanently stopped working. Even if a ventilator keeps their heart beating and lungs inflating, the person has no awareness, thoughts, or bodily function because the brain is no longer active.
What is brain death?
Brain death happens when all functions of the brain including the brainstem are lost permanently. The brainstem controls basic life functions such as breathing, consciousness, and heartbeat regulation. Without it, a person cannot breathe, respond, or survive without machines.
A brain dead person is not in a coma or a vegetative state. Those conditions involve limited or altered brain activity, while brain death means no brain activity at all.
Causes of brain death
Brain death can happen due to:
A severe head injury (e.g., from a gunshot)
Bleeding in the brain (e.g., from a stroke or aneurysm)
Brain infections (e.g., meningitis or encephalitis)
Lack of oxygen to the brain (e.g., after cardiac arrest or drowning)
These events can cause swelling, bleeding, or damage that stops oxygen and blood from reaching brain tissue, leading to its death.
How brain death is diagnosed
Doctors follow strict procedures to determine if someone is brain dead. The diagnosis is only made if they are absolutely certain.
To confirm brain death:
Doctors rule out any conditions that can mimic brain death, such as:
Drug overdose or poisoning
Very low body temperature (hypothermia)
Severe shock or low blood pressure
The patient must be in a deep coma with no chance of recovery.
The patient must show no brainstem reflexes, such as:
No pupil response to light
No blinking when the eye is touched
No response to pain
No gag or cough reflex
An apnea test is done to see if the patient can breathe without a ventilator. If they make no effort to breathe after being removed from the ventilator, brain death is confirmed.
Sometimes, additional tests like EEG (measuring brain waves) or brain blood flow studies may be used to support the diagnosis.
While brain death isn't diagnosed solely by radiology, imaging like CT or MRI can be part of the diagnostic process particularly when ruling out treatable causes or confirming absence of brain activity.
Can someone recover from brain death?
No. Brain death is irreversible. Once diagnosed, the person is legally and medically dead. There is no chance of recovery, no matter the cause or the treatment.
What happens after brain death is confirmed?
After brain death is confirmed, doctors will talk with the family about what it means. The following options may be discussed:
Organ donation: If the person is a suitable donor, their organs can be kept functioning temporarily using machines, so they can be donated to save others’ lives.
Withdrawal of life support: If donation is not an option, the ventilator and other machines will be turned off, and the body will soon stop functioning.
This is a sensitive and emotional time, and healthcare teams provide support and guidance to families.
FAQs
What is the difference between brain death and coma? A coma is a deep state of unconsciousness where brain activity still exists and recovery is possible. Being brain dead means there is no brain activity and no chance of recovery.
Is a brain dead person alive? Medically and legally, no. Even if machines keep the heart beating, the person is considered dead because the brain has permanently stopped working.
Can a brain dead person feel pain? No. Since all brain function, including areas that sense pain, is gone, the person cannot feel anything.
How long can a brain dead person stay on life support? A brain dead person can be kept on machines for a short period, usually to allow time for organ donation or family decision-making. The body will eventually stop functioning even with life support.
Can brain death be misdiagnosed? It is very rare. Strict and repeated tests are done by experienced doctors to make sure the diagnosis is accurate before it is confirmed.
Published 29th June 2025
References
- NHS inform. Brain stem death. Available at: https://www.nhsinform.scot/illnesses-and-conditions/brain-nerves-and-spinal-cord/brain-stem-death/
- Better Health Channel (Victoria State Government). Brain death. Available at: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/brain-death
- NHS.uk. Brain death. Available at: https://www.nhs.uk/conditions/brain-death/
- Cleveland Clinic. Brain Death: What It Is, Causes, Symptoms & Diagnosis. Available at: https://my.clevelandclinic.org/health/diseases/brain-death