Nurses are working in "intolerable situations", with many considering leaving the profession, according to a poll.
The Royal College of Nursing (RCN) survey of more than 4,000 nurses found many felt undervalued, with too many patients to care for and too much paperwork.
More than half (56%) said too much time was spent on non-nursing duties, with 59% too busy to provide the level of care they would like.
Some 43% have seen an increase in the number of patients they are being asked to care for, while 42% of those working in the NHS said there were recruitment freezes.
More than a third (34%) regard bullying and harassment as a problem in their workplace. Some 82% have worked when not well enough to do so and fewer than half (45%) would recommend nursing as a career.
Josie Irwin, head of employment relations at the RCN, said: "Nursing staff are being placed in intolerable situations, working themselves sick and still not feeling they have been able to deliver the care they would like.
"Many nurses skip every break, work late after every shift, do their paperwork in their own time, and the pressure just increases.
"Many are coming in to work despite being unwell, often due to work-related stress. This is no good for nurses, but we know it will have an effect on patients too."
Of all those surveyed, 29% of nurses said they did not feel nursing would offer them a secure job in the future.
Almost a third (31%) were seeking a new job, with almost a quarter looking to leave healthcare completely.
Over half (53%) said they worked extra hours to earn money to pay for bills and other living expenses, while 32% have worked nights or evening shifts for the same reason.
One nurse told the RCN: "I have to work late most shifts to ensure workload is complete. Too much paperwork and not enough patient care."
Another said: "The ward is intense and busy. We are running ourselves into the ground, not taking breaks and leaving an hour after shifts end to get all our work done. We should get paid a lot more for this amount of pressure."
Ms Irwin said: "Employers, the NHS and the Government need to work together to ensure that there are enough nurses, with the right level of skills, where they are needed.
"There needs to be a recognition that care is a part of all our futures, and we should value it, invest in it and train enough people to deliver it well."