Coventry's University Hospital: Planned surgery and clinics cancelled
All planned surgery and outpatient clinics were cancelled at a Coventry hospital because of a "high amount of very sick patients".
The cancellations at University Hospital on Wednesday - which did not include cancer surgery - were due to continue Thursday morning.
The hospital trust said patients would be contacted if their appointments or surgery were taking place.
The hospital said it was under a "considerable amount of pressure".
More than 500 people were seen in A&E on Tuesday, said University Hospitals Coventry and Warwickshire NHS Trust, and "dozens waited more than four hours".
Andy Hardy, the trust's chief executive officer, said: "Since midnight many others have waited longer than four hours and at 10:00 we had more than 60 in the department."
Walk-in blood tests in the outpatient department were also stopped on Tuesday.
The public was asked to consider alternatives to going to A&E.