By Nick Edser, Business reporter • Kathryn Armstrong, BBC News
Most GP practices in England have been disrupted by the global IT outage, the NHS has said.
GPs have been struggling to access their records systems, which include online bookings. Pharmacy services, such as access to prescriptions, have also been affected.
The outage has led to long queues at UK airports and has knocked some TV channels off air.
Cyber security firm Crowdstrike said the global IT problems were caused by a defect in a content update and was not a security incident or cyberattack.
“The issue has been identified, isolated and a fix has been deployed,” said George Kurtz, CEO of Crowdstrike.
Pat McFadden, Chancellor of the Duchy of Lancaster, said government teams were coordinating their response to the major outage through Cobra – the emergency response committee.
“Ministers are working with their sectors and respective industries on the issue,” he wrote on X, formerly Twitter.
The NHS said it was aware of the global outage and of issues with its EMIS system, which allows GPs to manage appointment bookings, conduct patient consultations, and update, store and share patient records.
“Patients should attend appointments unless told otherwise. Only contact your GP if it’s urgent, and otherwise please use 111 online or call 111,” an NHS spokesperson said.
They added there was no known impact on 999 or emergency services.
There have also been issues with community pharmacies, according to the National Pharmacy Association, “including the accessing of prescriptions from GPs and medicine deliveries”.
Professor Kamila Hawthorne, chair of the Royal College of GPs, said the outage was of “serious concern” and asked people to be patient as clinics worked to keep services going.
Neha from Ashford in Kent was among those affected, telling the BBC that the blood test she booked a month ago was cancelled this morning.
She was told by her GP surgery that they could not access some of their computer systems and would get back in touch to rebook the blood test when their systems had been restored.
“I was waiting for this test and now I have to wait again,” Neha said, adding that she felt “disappointed”.
Long queues have been reported at airports, and British Airways says some of its flights are “likely to experience disruption”.
The UK’s largest airport, Heathrow, said the outage was affecting “select systems”.
“Flights are operational and we are implementing contingency plans to minimise any impact on journeys”, it said in a statement.
Among those who were caught up in the delays were members of a hen do heading to Dublin from East Midlands Airport.
Anna Hindmarsh told the BBC that she and five other people due to travel for her sister’s four-day celebration had been left behind after being delayed when their bags had to be checked in manually.
“I’m really disheartened,” Ms Hindmarsh said, adding that they were now struggling to rebook.
A group of US tourists due to travel home to Texas from Edinburgh told the PA news agency that they were forced to pay more than £5,000 for new flights after their original plans were cancelled.
Some flights into the UK have also been disrupted. Jemma Wheeler, 30, said her family of five was stuck at Palma de Mallorca Airport after the IT issues caused delays at check-in.
“We thought it was a quick, two-hour flight and we would be back in no time to enjoy the nice weather at home,” she told the BBC.
Those waiting for their flights are being urged to keep an eye on communications from their airlines and to keep essential items in their carry-on if they check in bags.
Train services are still running, although the National Rail Enquiries website has warned of “widespread IT issues across the entire network”.
It said this could potentially lead to “short-notice train cancellations”.
“Additionally, other key systems, including real-time customer information platforms, are also affected,” it added.
It said services run by Gatwick Express, Great Northern, Southern and Thameslink may see alterations and cancellations.
British TV channels Sky News and CBBC are now both back on air after having been affected.
Additional reporting by Ian Casey & Dan Martin