A health board has decided to cancel all planned operations at its four hospitals due to "extraordinary" levels of pressure over the weekend.
Hywel Dda University Health Board said it was "in the interest of patient safety" to stop all inpatient operations at Bronglais, Glangwili, Prince Philip and Withybush Hospitals on Monday, January 6.
The cancellations continued into Tuesday, January 7. However, all outpatient appointments are continuing as normal.
The situation is so severe that staff currently on annual leave are being asked to come in and help.
A spokesman said critical pressures were being felt across all of its hospital A&E departments , GPs and our community services.
"We are contacting patients affected directly so please attend as planned if you do not hear from us," he said.
"Otherwise, please do not contact our appointments or outpatient teams unless absolutely necessary as they are very busy at this time.
"If you are unwell, please be aware that you may experience long waits for a GP appointment and at our A&E or minor injuries units units at this time, for which we wholeheartedly apologise.
"If there are other services you can use, such as community pharmacies, please do so."
The health board spokesman added that flu and norovirus are circulating in communities and warned people to stay at home with any symptoms.
The spokesman added: "However, if you are vulnerable (very young, frail elderly, living with long term or chronic conditions) or your symptoms worsen please seek medical advice."
Dr Philip Kloer, medical director at Hywel Dda UHB, said: "First I'd like to thank all my NHS colleagues across our hospitals, primary care and in the community for their commitment to our patients at this highly pressurised time.
"This weekend saw our hospitals at a level of escalation not seen before and it is in the interest of patient safety that we have postponed planned operations today.
"I understand this may be frustrating for those who have waited for their operation and I apologise for this.
"In response to the pressures being experienced today, we are redeploying staff to areas where additional support is needed, including contacting staff currently on leave.
"We are also working with our colleagues in the local authority and the families of those well enough to be discharged to ensure our medically well can go home or to an appropriate care setting as soon as possible."
Commenting on the cancelled operations, Plaid Cymru health spokeswoman Helen Mary Jones said the decision was "deeply concerning".
She said: "It is worrying that there isn't sufficient capacity in the system to deal with these pressurised situations when they arise and strongly suggests that there is a serious issue of under resourcing across the whole health and care system in the Hywel Dda University Health Board region."
