Hawke's Bay Hospital is at capacity.
People are being urged to seek medical care from their family doctor, medical centre, pharmacy or to call Healthline unless it's an emergency.
Chief Medical and Dental Officer John Gommans said the hospital had been busy for a number of days with patients presenting with a wide variety of illnesses and injuries.
Dr Gommans said people with minor injuries or illnesses, such as colds, could expect to wait for a long time as the Emergency Department prioritised patients needing urgent care.
"Emergency Department clinicians are highly trained in emergency care - caring for people with life-threatening injuries and illnesses. We are asking people to Choose Well when they are thinking about where to go for care. The Emergency Department is the place to go for life threatening and urgent treatment."
Pressure on the hospital is expected to remain until after the weekend.
For more information on where to find a family doctor and other health information people could check www.ourhealthhb.nz, which provided health information specifically for Hawke's Bay people. Healthline is also available 08 00 611 116 for free health advice 24 hours a day.
Although most practices will see urgent patients, it is not necessarily easy to get on the books of a practice in Hawke's Bay.
Thirty-two GP practices are listed on the DHB website. Of those, nine are said to have full books, 13 are taking patients with conditions, and 10 are currently enrolling.
In its latest GP Workforce Survey, the Royal College of General Practitioners warned about a national shortage of GPs.
In addition to the low and falling full time equivalent GP to population ratio, further evidence could be seen in the existence of waiting lists for patients wishing to enrol with a practice, and practices with closed books, the report said.
It is also noted that some regions within New Zealand struggle to attract GPs and in these locations vacancies remained unfilled for extended periods.