A report into end of life care has offered an insight into "appalling" incidents of patient neglect during the final moments of their lives.
These include a mother who was forced to call an A&E doctor from another hospital ward because her son was in such desperate need of pain relief, as well as an elderly cancer patient who suffered 14 painful attempts to have a drip reinserted during his final hours and "suffered unnecessarily at the end of his life".
The NHS has since been urged to consider the report and make changes as "too many people are dying without dignity".
The Parliamentary and Health Service Ombudsman's dying without dignity report said it has found too many instances of poor communication leading to families losing the chance to say goodbye to their loved ones, along with poor pain management and inadequate out-of-hours services.
Every year, approximately half a million people die in England and for three-quarters of them, death is not sudden but is expected, the report said.
Many of these people may benefit from end of life or palliative care, with much that can be done to improve the last months of around 355,000 people's lives.
The ombudsman, which makes final decisions on complaints about the NHS in England, looked at investigations it had completed from GP practices to hospitals and mental health trusts, to identify the issues it sees the most often.
It found "tragic" cases where people's suffering could have been avoided or lessened with the right care and treatment as they approached the end of their lives.
The report said the 74-year-old cancer patient, referred to as Mr C, "suffered unnecessarily at the end of his life" as staff "failed to provide treatment to ease (his) discomfort in his final hours".
It was clear from his medical records that the hospital knew he did not have long to live, but despite this, staff did not recognise that a drip was no longer an appropriate treatment option for someone so close to death.
He was subjected to 14 unnecessary attempts to reinsert the drip, which would have caused him further pain and discomfort in his final hours.
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The report also features the story of a mother who was forced to call an A&E doctor from another hospital ward as a last resort to get her 29-year-old son pain relief.
The family knew nothing more could be done to treat his cancer, and the investigation found he experienced unnecessary pain and distress for more than 11 hours while in a palliative care unit because the on-call doctors did not respond to a request to review his pain medication.
The report found that the way a 67-year-old man's family learnt of his terminal cancer diagnosis through a hospital note - and before he knew himself - "failed every principle of established good practice in breaking bad news".
"There was an avoidable delay in making a diagnosis," it added. "An earlier diagnosis would have meant opportunities for better palliative care."
Ombudsman Julie Mellor said the NHS should consider the report to help prevent similar cases from happening again.
"Our casework shows that too many people are dying without dignity," she said.
"This report highlights the impact on patients and their loved ones, when the care and treatment of people nearing the end of their lives, falls short.
"Our investigations have found that patients have spent their last days in unnecessary pain, people have wrongly been denied their wish to die at home and that poor communication between NHS staff and families has meant that people were unable to say goodbye to their loved ones."
Dr Peter Carter, chief executive & general secretary of the Royal College of Nursing, said: "The stories told in this report are heartbreaking. Despite the focus on dying in recent years, too many people are experiencing needless suffering at the end of their lives - suffering that will stay with loved ones for years to come.
"The truly sad thing is that there are many things we can do to make people's experience at the end of their lives better.
"There must be enough staff available either in hospital or in the community to properly listen to the needs and concerns of dying people and their loved ones. Had this support been available for the families in the report, the ombudsman's intervention would not have been needed."
Chief executive of Macmillan Cancer Support, Lynda Thomas, said: "This report highlights a catalogue of dispiriting, avoidable failings that cause great distress to people at the end of life and their families.
"If we are to improve the current situation we will have to see a dramatic improvement in coordination of care, and greater integration of health and social care.
"Earlier this year the Health Select Committee strongly recommended free social care for people at the end of life, which is a measure we would urge the new government to give careful consideration, as it will allow people their dying wish to stay at home, as well as reduce expensive, unnecessary emergency admissions."
An NHS England spokeswoman added: "This powerful report echoes the need for changes that were recently set out in the NHS' Actions For End Of Life Care to ensure that people get the support they need to live well and die according to their wishes."