Bethany Shipsey died aged 21 last year after a series of delays and medical errors during treatment at the Worcestershire Royal Hospital near her Worcester home.
The Worcestershire coroner Geraint Williams recorded a conclusion of suicide in the death of Bethany Shipsey but added that a series of failings in her care in a busy A&E department amounted to failures in basic medical care.
Miss Shipsey was admitted to A&E in Worcester in February 2017 following an overdose of DNP diet pills but the coroner could not conclude she would have survived if she had received the full package of care.
After the conclusion, her parents said they were "very disappointed".
In a statement read outside the court, they said: "We do not feel that the coroner's conclusion reflected the evidence that was heard during the inquest."
They added: "Bethany's basic human right to life was breached in the very place you would expect it to be preserved."
The overdose was Miss Shipsey's 15th, and she was also a mental health outpatient following an abusive previous relationship.
Her mother Carole Shipsey, who is a trained nurse, told Sky News how they counted 27 patients being treated on trolleys in corridors that night.
She said: "There was no communication with us, there was no respect or dignity.
"Bethany literally went in on a trolley that night and she died on a trolley."
Miss Shipsey had been moved between four different bed spaces within the A&E department during her treatment.
:: Overdose woman Bethany Shipsey died after 'A&E was overwhelmed'
The first emergency junior doctor to see her that night, Dr Alireza Niroumand, had never treated a patient who had taken DNP diet pills and then failed to consult the Toxbase service where medics can find appropriate advice.
Mrs Shipsey added: "Even if he was overwhelmed or the hospital was overwhelmed it was essential information that wasn't read, and if part of it was read it wasn't acted upon....that started a chain of events that ultimately ended in Beth's death - it didn't give her a chance."
Experts disagreed during the inquest as to whether better treatment could have saved Miss Shipsey but medical staff conceded their department was classed as "overwhelmed" that night.
Senior nurse Kirsty South broke down in tears during her evidence as she described "one of the most challenging shifts we have ever worked....it would be wrong for me to say that it doesn't occur regularly".
Miss Shipsey's father Doug told Sky News that the hospital had since admitted to him that there was a "system failure".
He said: "Since Beth's death we are hearing more and more deaths attributed to overcrowded and overwhelmed hospitals.
"This is the UK, it is not a Third World country or a war zone."
"We need the Government to stop making excuses.....we need them to actually listen to their regulators, we need those regulators to act, the Government to act quicker and sooner and realise that ultimately they are complicit in the serious harm and death that people are succumbing to in Britain's hospitals."
The Care Quality Commission currently rates the Worcestershire Royal Hospital as "inadequate" and the Worcestershire Acute Hospitals NHS Trust remains in "special measures".
Following the inquest's conclusion, the trust said in a statement: "We would like to express our deepest condolences to the Shipsey family for the tragic loss of their daughter Bethany.
"We are sorry for the shortcomings in Bethany's care and the support which was offered to her family.
"We can reassure people using our urgent care services that we have taken actions since February last year that address the issues highlighted by the coroner today."
The trust said these actions included increasing staff numbers, having a clear policy on poisons and improving the way in which medical professionals recognise patients whose condition is deteriorating, meaning action can be taken more quickly.
They added: "While we are reassured that our inspectors have found improvements in the safety and effectiveness of care in A&E we recognise that we still have work to do, and that work will continue."
