An 86-year-old grandfather fell while walking home after discharging himself from hospital after a fruitless 15-hour wait at A&E.
Brian Hooker, who suffers from lung disease and mobility difficulties, was left waiting overnight at Medway Maritime Hospital in Gillingham, Kent, in the hope of seeing a doctor.
His condition was serious enough to be taken there by ambulance, but after waiting 15 hours for help, he finally gave up and started walking a 40-minute route home.
Hooker suffered a fall on the journey, but luckily passers-by came to his aid and drove him the rest of the way back.
The pensioner's son, Lawrence Hooker, believes his father could have died if he had fallen and hit his head, or suffered a serious injury.
He called for hospitals to do more to ensure vulnerable people are not forgotten about if they decide to walk out of A&E, suggesting family members should be contacted by staff.
He said: "Because he doesn't have a diagnosis of dementia they'll let him self-discharge. To some extent that's one person off their list, isn't it?
"That's just the reality of life when people are beaten down to the extent that the nursing staff are. They don't have the energy to worry about chasing someone out into the street if they want to go home."
During the run-up to Christmas, Medway Maritime Hospital declared a critical incident over lack of capacity as the number of patients going to A&E rose, allowing staff to take additional steps to maintain safe services.
Across the country at least seven NHS trusts have declared critical incidents, as a shortage of hospital beds means patients are being forced to wait in ambulances parked outside.
Hooker, who volunteers as a trustee at the hospital trust, says he understands the pressure frontline staff are under and does not blame them for A&E delays, but warns a lack of capacity could have potentially fatal consequences.
He said: "Lives are being put at risk because of this. When he fell down on the way home it's pure statistical chance whether he smacks his head on a kerb stone, or the worktop in the kitchen, or the floor, and kills himself."
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Hooker is one of many vulnerable patients who have been stuck in hospital. Paul Coombs who suffers from dementia, was left sitting in an A&E corridor for 24 hours.
The 72-year-old from Sittingbourne, Kent, spent more than a week at Medway Maritime after he was taken from his care home on 18 December after contracting a urinary infection.
His daughter, Laura Kanareck, claims he lost eight pounds during his stay after the family's instructions that he needed help eating and drinking "fell on deaf ears".
Jayne Black, chief executive of Medway NHS Foundation Trust, said: "We apologise for the long wait experienced by Mr Hooker, and invite both him and his family to contact us directly so we can investigate their concerns.
"We continue to see high demand in our emergency department. Patients are prioritised according to clinical urgency and our staff are working tirelessly to ensure all patients are seen as quickly as possible."
"The public can help to ease the pressure by only attending our emergency department if you have an immediate life-threatening need."