The North West Ambulance Service has declared a major incident due to the high level of activity in the North West region, in particular the Greater Manchester area.
The service say they are exceptionally busy.
If your call is not life-threatening, you may be asked if you can seek an alternative source of care or make your way to hospital by alternate means.
A spokesperson said: "You can help us reach the patients that urgently need our help by not calling 999 unless the condition is life-threatening or potentially life-threatening, not calling us to find out where your ambulance is or calling to cancel any ambulance that you no longer require or feel is necessary.
"We are trying our best to reach patients as soon as we possibly can and apologise for any delays in our response. Please bear with us."