Aneurin Bevan University Health Board says its hospitals have reported their busiest January on record.
The number of people being seen at A&E and Minor Injuries Units in the area in January 2019 increased by 12% from five years ago.
The health board says the number of people accessing NHS services is on the rise due to an increased population and people living longer.
Executive Director of Operations at the Health Board, Claire Birchall, thanked staff for their hard work and patients for their "understanding and patience" during busy periods.
The health board is asking the public to only consider visiting its Emergency Departments "if they really need to".