Thousands of health workers, patients, union members and activists will join a march in London on Saturday to demand an end to the "crisis" in the NHS.
The Government will be urged to provide more beds, staff and funds to ease the problems facing the service.
The event, called 'NHS in crisis: Fix it now', is being organised by the People's Assembly and Health Campaigns Together.
Activists will march through central London from noon before holding an hour-long rally opposite Downing Street.
Actor Ralf Little recalled how his mother suffered a stroke and had been saved by NHS staff for free while his mother-in-law paid thousands for a routine operation in Florida.
He said: "My mother-in-law spent two nights in hospital, had a minor operation, and was discharged two days later. She has excellent insurance so was only presented with a bill for $2,500.
"My mother was rushed to hospital in an ambulance, received expert emergency care, stayed in hospital for two weeks to recover, was treated daily by consultants, physical therapists, occupational therapists and nursing staff, was escorted home in a taxi and checked on three times a day for a further five weeks."
Shadow health secretary Jon Ashworth, who will attend the demonstration, said: "We should be celebrating the 70th year of our NHS, yet the NHS is going through its worst winter on record. We have a fight on our hands for the future of a universal public NHS."
TUC general secretary Frances O'Grady said: "Our NHS is in intensive care, starved of the resources necessary to meet the needs of our ageing and diverse society.
"Meanwhile, brilliant, dedicated staff have suffered year after year of pay misery and are having to do more, with less, for less. "
Royal College of Nursing president Cecilia Akrisie Anim will address the rally and say: "Nursing staff are bearing the brunt of the enormous pressures facing the NHS.
"Staff at every level are experiencing burnout and many of our colleagues are turning their back on jobs they love. It's no surprise that nursing staff feel overstretched and undervalued. There are now more than 40,000 nurse vacancies in England alone.
"2018 is 70 years since the formation of the NHS and nurses have always been at the heart of it. Urgent action is needed to address the current crisis - if none is taken, it is our patients who will suffer. We will continue to speak out to defend our NHS."