More than 200 GP practices across England have closed or merged in the last year, figures show.
Data from NHS Digital reveals that while just eight practices opened, 202 closed or merged together.
Practices closed in all regions, but the North of England was particularly hit, with more than 60 closing or merging - while more than 50 closed or merged in the South East.
Those that opened were mainly in the Midlands and the East of England.
It is unclear how many patients may have lost a GP or had to move to another practice.
A Pulse magazine investigation in April suggested more than a quarter of a million patients may have been forced to change surgery in 2016.
Its data was based on more than 90 GP surgeries.
Four of those closures meant 9,000 patients had to find a new surgery, it said.
Last year, NHS England announced a £500 million "turnaround package'" to help struggling surgeries, including those at risk of closure.
NHS England data shows that between last summer and this - the same time period covered by the 202 closures and mergers - more patients became registered with GPs across the entire country.
Taking into account the fact some patients may register with more than one GP, 58,492,541 patients were registered with a GP on July 1 this year.
This is up on the 57,744,814 registered at the same point last year, and the 57,111,235 the year before.
Professor Helen Stokes-Lampard, chairwoman of the Royal College of GPs, said: "It's not clear with these figures why practices have closed - some may have merged, and others may have closed as a result of working 'at scale', which can bring benefits for patients through pooling resources to provide additional services or better appointment access.
"But this won't always be the case and when practices are being forced to close because GPs and their teams can no longer cope with ever-growing patient demand without the necessary funding and resources, it's a huge problem.
"And when practices are being forced to lock up and hand back the keys to their surgery because they can't recruit enough GPs or practice staff, it will have severe consequences for our patients and the wider NHS.
"More research into why practices are closing would be really useful - but ultimately, we need the pledges in NHS England's GP Forward View, including £2.4bn extra a year for general practice and 5,000 more full-time equivalent GPs by 2020, to be implemented in full and as a matter of urgency."
Dr Richard Vautrey, acting chairman of the British Medical Association's GPs committee, said: "The Government has long ignored GPs' warnings that general practice is struggling to cope, but this is further evidence that the service is at breaking point.
"With over 200 practices closed or merged in the last year and many more struggling to manage their workload pressures, it is time for Government and NHS England to step up their efforts to resolve this crisis before even more patients lose their much loved local GP service."