By Nick Triggle Health correspondent
Shortages of nurses in the NHS are posing a risk to patient safety, the Royal College of Nursing is warning.
RCN general secretary Pat Cullen said patients were going without the care they needed because of the problems.
Feedback from the union's members in the UK cited people going without medicines and deterioration of sick patients going unnoticed as concerns.
One in 10 nurse posts in England is unfilled. But the numbers working in the NHS is rising, the government said.
Ms Cullen will set out her concerns in detail during her speech to the RCN's annual conference, which is getting under way in Glasgow.
It comes after the union gathered feedback from more than 20,000 nurses across the UK about their experiences during their most recent shifts.
They voiced concern about safety, the union said, with members saying patient care was being compromised.
Nurses cited everything from basic personal care, such as helping patients going to the toilet, through to severely ill patients getting treatment late and medicines not being given.
The feedback suggested the problems were being seen across the UK in all types of settings from hospitals to care in the community and in mental health services.
Hospital staff reported sometimes having to treat patients in inappropriate settings, such as waiting rooms and corridors, because of the time pressures.
Nurses also provided feedback setting out how the situation was affecting their wellbeing with one saying: "Myself and my colleagues are mentally, physically and emotionally exhausted and burnt out."
Ms Cullen will tell members at the conference that "enough is enough".
"Don't ever think that it is normal to not have enough staff to meet the needs of patients. It is not.
"Today members are letting the full truth be known."
Ms Cullen warned the stresses on the frontline were beginning to drive nurses out of the profession.
Figures from the Nursing and Midwifery Council show 25,000 nurses and midwives left the register last year in the UK - more than were trained domestically - although there are more nurses in total as a result of international recruitment.
"Staff are being driven out by the current way of working - the shortage of staff and too often the poor culture," Ms Cullen will say.
All parts of the UK have set out plans to increase the number of nurses working in the NHS.
The latest figures show there are now 321,000 nurses working in the NHS in England - 30,000 more than in September 2019.
The Department of Health and Social Care said this showed that, despite the problems being documented, the government in England was over halfway to recruiting the 50,000 extra nurses it had promised by 2024.
"We're grateful to all the healthcare staff for their tireless work," a spokeswoman added.
Meanwhile, a Scottish government spokesman said student places were being expanded and there was an international recruitment drive. "Growing our workforce is crucial," he added.
Call for long-term plan to help 'burnt-out' nurses
Student nurse ventilated with Covid returns to work
Should university students get a refund?
Nursing shortage warning as winter looms
Putin positions himself as heir to Peter the Great
Mariupol at risk of major cholera outbreak - UK
Trump dismisses daughter's testimony on voter fraud
War crimes give Ukraine's local prosecutors a new calling
War prompts regional rush to join EU
The woman changing Australia's rape laws
Why I don't want to forget Covid grief and loss
The 'sleepy' girl who changed India cricket forever
Hundreds jostle for a drop of water in India state. Video Hundreds jostle for a drop of water in India state
Are attacks on Christians in Nigeria on the rise?
Emma Thompson wants to talk about sex. Video Emma Thompson wants to talk about sex
Dinosaurs, shipwrecks and other photos this week
The 12 best films of 2022 so far
From Top Gun: Maverick to Turning Red and Everything Everywhere All at Once
Switzerland's ingenious cooling caves
When fridges didn't exist, locals had to find other ways to keep food cool
Why people believe their own big lies
The role self-deception plays in leading people astray
© 2022 BBC. The BBC is not responsible for the content of external sites. Read about our approach to external linking.