As many as half the country's GP clinics are not enrolling new patients, and others are asking people to wait weeks for an appointment.
Family doctors say they are grappling with a concoction of winter illnesses, Covid-19 infections and short-staffing which could worsen before it gets better.
Auckland GP Sandhya Ramanathan compared recent busy days at Surrey Medical Centre to being in a "warzone".
Many patients had been seeking help for Covid-19 infections - first time cases and reinfections - while viruses like the flu had also been tracking upwards, she said.
"Then there's also RSV, and other influenza like illnesses. So it is very busy at general practice at the moment and GPs are concerned because even patients without previous medical conditions are getting quite sick."
Across the country, there are fewer GPs to share this workload than a couple of years ago, because the workforce has been declining.
At any given time, a number are also having to isolate with Covid-19.
While it was only the early days of winter illnesses, Ramanathan said burnout was becoming a "huge issue" for fellow GPs.
"As GPs, as doctors, we took an oath to do no harm to our patients. But we didn't take an oath to do harm to ourselves," she said.
"We still come to work and do the best we can. But the patient issues are becoming increasingly complex, and in terms of paperwork there is a lot more we have to do ... and obviously we've been flexible in learning, providing vaccination and all sorts of things related to Covid."
One option GP clinics had to manage the demand was to simply say no to new patients.
And many are doing exactly that, according to Healthpoint.
It showed no GP clinics taking new enrolments anywhere in the cities of New Plymouth or Invercargill.
Across the whole Wairarapa region, just two practices were taking new enrolments out of 12 in total - with no option for people to enrol in Martinborough, Greytown or Carterton.
In Northland, where more than half the GP practices already had their books full, the were no clinics enrolling new patients in the towns of Russell, Kaitaia or Kawakawa.
Royal New Zealand College of GPs president Dr Samantha Murton said it was the same situation "across the board".
"If you look in any of the different the regions probably about 50 percent of practices are not enrolling patients. And that's just because of the workload involved. You can't reliably provide care to more than a certain number of patients," she said.
Meanwhile, people who were enrolled have reported waiting weeks for an appointment.
In Kaiwaka, Shanna Sutherland was feeling discouraged after her attempts to see the regular doctor who had been treating her sore shoulder for four years.
"I can't get to see my doctor. I rang up, can't even get a telephone appointment with a GP [for another four days], with a GP that I don't even know," she said.
Rose Kiddie was trying to avoid visits where possible, partly put off by "terrible" stories from friends.
"I had a friend who went, this last week... she got turned away and tried to explain to them what was wrong with her. She ended up having to go on the Saturday and paying $50 - it was pretty steep," she said.
GPs are putting the blame at the feet of the government.
The general practice association GenPro has criticised years of underfunding and under-resourcing.
It feared clinics would have to slash services further because the government's 3 percent funding increase for family doctors this year fell short of inflation.
Ramanathan accused the government of failing to put in place a comprehensive management plan for Covid-19 beyond the vaccine rollout.
"We need the government to step up and help with the workload," she said.
Problem brewing for some time - Betty
Royal New Zealand College of General Practitioners medical director Dr Bryan Betty said the shortage of GPs was not just a rural problem anymore.
Betty told Checkpoint it was becoming very serious in several areas - Northland particularly, Invercargill, parts of Hawke's Bay, South Taranaki, east Porirua and South Auckland.
He said it was a problem that had been brewing for some time.
"The recommended safe level is one GP to about 1300, 1400 patients. There are GPs with one to 2000 around the country, now 2500. And there are only so many hours in the day.
"GPs are working at capacity. This is the issue. It's not that they don't want to see their patients. It's not that they don't want to service their patients' base. It's just that the workforce numbers don't allow it, and this is the problem that has developed."
It was leading to overwhelmed emergency departments and a spike in the demand for ambulances, Betty said.
Ramanathan and a number of other prominent medical experts - including the likes of Michael Baker, Amanda Kvalsvig, and Joel Rindelaub - have launched a website called Vaccines Plus, lobbying the government to do just that.
It features an open letter signed by more than 200 doctors.
"We really need a 'vaccines plus' approach, and that 'vaccines plus' approach means that masks need to be used, particularly, I'd say, in schools, in the wintertime, indoors. And also we know that Covid transmission is airborne, so ventillation is key. I don't think that message has been put across adequately," Ramanathan said.
If the situation did not change, and the government kept relying on peoples' "personal responsibility", the Vaccines Plus group warned the prognosis would be gloomy.
It said that would result in "repeated waves of infection, an overloaded and dysfunctional healthcare system, and ongoing disruption to daily life".