Two thirds of the region's accident and emergency units are missing waiting time targets, latest figures have shown.
Hospitals aim to see 95% of A&E patients within four hours, a target not being met by 11 of 16 hospitals in the Anglia region.
This week all three of Cambridgeshire's major hospitals have been on so-called black alert which is an NHS hospital's highest state of alert after green, amber and red.
Addenbrooke's Hospital in Cambridge, Hinchingbrooke in Huntingdon and Peterborough City Hospital are all seeing patient numbers rising.
A black alert can mean a hospital is at full capacity, admissions are temporarily closed and routine surgery is being cancelled.
Dr Gary Howsam of the Cambridgeshire & Peterborough Clinical Commissioning Group said: "The whole of the system is creaking at the moment and that's social care, community care, primary care, your GP teams and the hospitals. That's why we've got to find a solution across the patch."
Hospitals which missed A&E waiting time targets
- (1) Addenbrooke's: 71.2% of patients treated within four hours
- (2) Hinchingbrooke: 76.5%
- (3) Milton Keynes: 79.8%
- (4) Peterborough and Stamford: 82.7%
- (5) Colchester: 86%
- (6) QEH King's Lynn: 88.4%
- (7) Kettering: 90.5%
- (8) Basildon: 90.6%
- (9) Norfolk and Norwich: 90.9%
- (10) Southend: 92%
- (11) Paget: 94%
Hospitals which met targets
- (1) Northhampton General: 98.8%
- (2) Luton and Dunstable: 98.8%
- (3) Bedford: 96.6%
- (4) Ipswich: 96.3%
- (5) West Suffolk: 95.1%
A&E waiting time figures are published weekly by the NHS.
Colchester Hospital in Essex declared a "major incident" last week, asking patients to stay away from its A&E department unless they have a serious or life-threatening condition and postponing operations.
This was on the back of a surprise inspection by the Care Quality Commission where the health regulator raised "safeguarding concerns".