Hospitals across the United Kingdom remain on high alert as an aggressive strain of flu sweeps the nation, pushing patient numbers to record levels and straining an already stretched National Health Service. With the festive season in full swing and the prospect of a second surge looming in the new year, health officials and government leaders are urging the public to stay vigilant, get vaccinated, and avoid unnecessary risks—especially as resident doctors continue to strike over pay and working conditions.
According to data released by NHS England and reported by multiple outlets, an average of 3,140 patients were hospitalized with flu each day in the week ending December 14, 2025. This figure marks the highest ever recorded for this point in the winter season—an 18% increase from the previous week, though the rate of growth has slowed compared to the alarming 55% jump seen earlier in December. The UK Health Security Agency (UKHSA) cautioned that it’s still too early to say whether the flu season has peaked, as flu often lingers into the new year and can bounce back unexpectedly.
Behind these numbers lies a complex and fast-evolving situation. The dominant strain, H3N2 'subclade K', has undergone several mutations, making it distinct from the version included in this year's flu vaccine. This so-called 'super flu' has reduced the population’s built-up immunity, contributing to the sharp rise in cases. As reported by the BBC and other sources, the impact is not uniform across the UK: while Wales, Scotland, and Northern Ireland have seen hospital flu cases start to drop, England—particularly regions like the East and South West—is still experiencing significant increases. In the North West of England, hospitalizations have actually fallen by 4%, but the East has seen a 39% rise and the South West a 40% jump.
Several hospital trusts are feeling the brunt of this surge. University Hospitals Birmingham NHS Foundation Trust reported an average of 249 flu patients daily, up 14% on the previous week. Sheffield Teaching Hospitals saw a 44% increase to 103 patients, while Barts Health in London recorded a 19% rise. Manchester University, however, saw a slight decrease in flu admissions, down 2%.
The pressure isn’t just about patient numbers. Hospital bed occupancy reached an average of 94.2% last week, a figure that leaves little room for flexibility. Staff absences have also climbed, with over 1,100 more employees off sick in a single week and a 9% increase compared to two years ago. Medical professionals themselves are being struck down by seasonal illnesses, compounding the strain on the health service. As one GP told the BBC, clinics are being run at “maximum” capacity.
Layered on top of these challenges is the industrial action by resident doctors, who began a five-day strike over pay disputes—a move described as “regrettable” by Health and Social Care Secretary Wes Streeting. The strikes have added significant pressure to hospitals, which are already grappling with a “stream of winter viruses,” according to Professor Meghana Pandit, NHS National Medical Director. “While some parts of the country will be breathing a sigh of relief with flu cases not rising as quickly as feared, we are nowhere near out of the woods yet,” Pandit said. “Combined with the impact of strikes, a stream of winter viruses means many hospitals will be on high alert in the days ahead. But it remains vital that people continue to come forward for NHS care as normal.”
Despite these daunting numbers, there are glimmers of hope. Health officials have noted that the rise in flu cases appears to be slowing, a trend thought to be linked to higher vaccination rates and increased public awareness. More than 18 million people have received a flu vaccine so far this season—306,000 more than the same week last year. This effort has not gone unnoticed by government leaders. “Flu continues to put significant strain on the NHS, with record numbers of patients in hospital, and frontline services remaining under enormous pressure,” Streeting said. “I’m appealing to the public to protect yourself and your loved ones by getting your flu jab. I want to thank NHS staff who are going above and beyond at the toughest time of year.”
Still, the situation remains precarious. Critical care beds occupied by flu patients rose from 106 to 128 in just one week, and hospital beds filled daily by patients with diarrhoea, vomiting, or norovirus-like symptoms jumped by 21% to 427. Hospital admission rates for flu plateaued at 10.3 admissions per 100,000 population last week, but the highest rates were among the most vulnerable: people over 85 had an admission rate of 64.6 per 100,000, and children under five saw their rate rise to 27.3 per 100,000.
Experts warn that the unpredictability of flu means the nation must not let its guard down. Dr. Alex Allen, a consultant epidemiologist at the UKHSA, emphasized, “With Christmas just around the corner, it’s reassuring to see that flu levels are now starting to stabilise, but flu is notoriously unpredictable and can bounce back and peak a second time in the new year, and so we’re urging people to continue taking sensible steps over the festive period to help stop the spread.”
Those steps include washing hands regularly, ventilating indoor spaces, staying home if symptomatic, and—crucially—getting vaccinated. Asthma sufferer Scott Blackwell, who nearly died from the flu in the winter of 2019-20, is among those urging the public to act: “Just get it done,” he said, highlighting the importance of vaccination.
In the face of the ongoing crisis, the NHS is also urging patients not to delay seeking care. Even as ambulance handover times have improved by nearly eight minutes compared to last year and the percentage of patients waiting more than 30 minutes to enter A&E has dropped from 32% to 28%, the health service remains under intense strain. “If you need urgent help, dial 999 in an emergency, or use NHS 111 for other care needs. And if you are eligible, please come forward for a jab, it’s not too late,” said Professor Pandit.
As the UK enters the final stretch of 2025, the message from health officials, government leaders, and frontline staff is clear: stay vigilant, take precautions, and support the NHS by getting vaccinated and seeking care when needed. The coming weeks will test the resilience of both the health system and the public, but with continued collective effort, there’s hope the worst of the flu season can be weathered.
