Video report by Katie Oscroft
Health chiefs at Chesterfield Royal Hospital say they are under "extreme and sustained pressure" – and are trying to work out why services are so stretched.
Medical staff with many years' experience told ITV News they had never experienced anything like the current climate.
Figures show that 40% of patients arriving at the emergency department last month waited longer than the target of four hours – five times higher than pre-pandemic levels.
Joy Gould, a sister in the emergency department, described the past three years as the biggest challenge in the whole of her career.
"Some days there are people lined up in the corridors, and you can't do anything with them, there's nowhere to put them because of the pressures, you're trying to move them to wards but there are no beds," she said.
The deputy chief executive, Berenice Groves, said that services were under "extreme and sustained pressure" and research was underway to try to find out why.
She said: "What we are all trying to understand is where some of the activity is coming from, because we are actually seeing pressures on services right across the board.
"Whether it's our emergency departments here at Chesterfield, whether it's our ambulance trust, whether it's primary care, we're actually seeing increased activity coming through the doors.
"Some of it will be the after effects of Covid, people have kept themselves away from health care and we're starting to see those surges coming back. But some of it is absolutely about making sure that we promote self-care wherever possible."
The latest figures show show that more than a third of patients have been waiting for surgery at Chesterfield hospital for longer than the target of 18 weeks.
Last month the average response time for the East Midlands Ambulance Service attending the most urgent incidents was over nine minutes. The target is seven minutes.
Patients are being urged to use online and phone services as well as pharmacies and walk-in centres unless they need emergency care.
Hospital staff had invited us in on International Nurses' Day and urged people to join their profession in spite of the challenges.
A Department of Health spokesperson said: "Demand for the NHS is rising. We are working to tackle the Covid backlog so patients can be seen quicker.
"We are opening new surgical hubs and community diagnostic centres so patients have easier access to tests closer to home.
"This is backed by record investment from the Health and Care Levy, with over £36 billion over the next three years."