The three reasons you could be declared officially dead whilst still alive
Waking up in a coffin or laying in a funeral home is likely almost everyone's idea of their worst nightmare.
But just earlier this month, that horror became a reality for one 82-year-old pensioner who was pronounced dead at a nursing home before later being found alive by funeral home staff.
The pensioner was a resident at Water's Edge Rehab and Nursing Centre, and staff thought she had died.
She was moved from the care home on Long Island, New York State, to OB Davis Funeral Homes, at 11.15am on Saturday, February 4, where she was discovered breathing just over half an hour later.
The woman was then taken to hospital for treatment and officials are now investigating, as this incident comes just weeks after a similar incident occurred in Iowa.
Baby boy has spent his life in hospital as doctors are 'scared' to discharge himThe care home in Iowa was fined $10,000 (£8,185) after a funeral home discovered a woman in a body bag who was still alive.
However, there are a few rare scenarios where someone could technically be declared dead while still alive, as explained by medical Professor Stephen Hughes from Anglia Ruskin University.
Cold Water
Cold water immersion can mimic signs of death due to a rapid slowing down of the heart rate.
The professor said doctors taught that a drowned patient is "not proven dead until they have been warmed up".
The sudden immersion in cold water results in an immediate decline in skin temperature which, in turn, initiates shivering, increases metabolism, ventilation, heart rate, and cardiac output.
As body temperature declines and shivering ceases, these all decrease proportionally with the fall in core temperature.
Kidney function changes can also lead to a considerable loss of the amount of fluid surrounding body tissue
Drugs
Sedation drugs used by doctors can sometimes reduce responsiveness and slow down breathing and circulation
This means people can sometimes appear dead, said Professor Stephen Hughes.
In The Conversation, he said: "Later on, as the drug is cleared from the body, the person may wake up."
Disabled woman paralysed after falling from wheelchair on plane walkway diesAnxiety drugs, diazepam and alprazolam have both caused people to mistakenly be declared dead.
Shock
Shock cans sometimes be so severe that it triggers fainting, and deceives the certifying doctor into thinking someone has died before their time, he explained.
Fainting can trigger the vagus nerve, our major communications link between the brain and the body - which slows down the heart and reduces blood flow.