Admissions to A&E in six hospitals including those in Leeds and Harrogate have seen a 14.1 per cent rise compared to this week last year.
Some patients are having to wait 12 hours to be seen from when they present in emergency wards, the West Yorkshire Association of Acute Trusts (WYAAT) revealed.
The NHS waiting time target in emergency departments is four hours, but some 28 per cent of the 24,470 patients who presented at A&E departments in Leeds in February had to wait longer.
Airedale, Calderdale, Bradford and Wakefield’s hospitals are also all experiencing significant pressure, WYAAT said, with the situation worsening significantly over the past two weeks.
Dr Andrew Lockey, emergency medicine consultant with Calderdale and Huddersfield NHS Foundation Trust, said: “It’s really important that people only come to an accident and emergency department if they really need to.
“Our hospitals are extremely busy, and people are having to wait a long time to be seen.
“Over the past two weeks we’ve faced huge challenges with the sharp uplift in the number of people attending accident and emergency. This places additional pressure on our teams who are responsible for treating patients with serious and life-threatening conditions.”
The NHS Confederation, which is a membership body representing healthcare staff, said the workforce is “exhausted” amid pressures leading to ambulance delays and critical incidents being called.
Dr Layla McCay, director of policy, said: “Ambulances, A&E departments and front-line providers of care across all parts of the NHS are weighed down by heavy demand.
“Healthcare leaders and their exhausted teams are doing their utmost to provide patients with the treatment they require, but with 110,000 vacancies across the NHS, they also need urgent support from Government to address severe workforce shortages.
“Healthcare leaders would urge the Government to have a realistic conversation with the public about the current situation in the health service.”
Labour also attacked the Government for “lowering standards” across healthcare.
Andrew Gwynne, Shadow Health Minister, said: “A decade of Conservative under-investment left the NHS unprepared to cope with the current pressures, so patients are going without the care they need. Instead of lowering waiting times, the Government’s answer is to lower standards for patients.”
NHS England was approached for comment.