The NHS is urging people to avoid going to hospital if they are experiencing flu-like symptoms, over fears that it could seriously harm the patients there.

London North West University Healthcare Trust is among those to have issued the advice, noting how hospital patients can be particularly vulnerable to viruses.

The UK has witnessed a surge of infections from flu this year, with around 4,000 people admitted to hospital. Since December, Northwick Park Hospital has seen 94 patients test positive for flu, while Ealing Hospital has seen 79.

More than 4.5 million people across the country are believed to have experienced flu-like symptoms but, in most cases, would not require hospital treatment.

Infectious diseases consultant Dr Bill Lynn said: “Influenza can be dangerous for patients who already require medical treatment.

“None of us would want our loved ones to be put at risk by the virus, and that’s why we’re asking for the public’s support in stopping flu from spreading wherever possible.

“Please help us protect our patients by staying away from hospital if you have two or more flu symptoms.”

The flu-like symptoms that the public is asked to watch out for include a fever, headache, shortness of breath or cough, runny nose, sore throat, tiredness, aching limbs, lack of appetite, vomiting and diarrhoea, and stomach cramps.

Dr Lynn added: “In most cases, hospital isn’t the best place to care for someone with flu – it’s usually best to rest at home, stay warm, and drink plenty of water so that you keep hydrated.

“If you are concerned about being unwell, you should call the 111 helpline for advice or your GP surgery.”

London North West University Healthcare NHS Trust is asking patients who have a booked appointment to reschedule it if they experience two or more of ten symptoms commonly associated with flu.

Those planning to visit the hospital to see friends or relatives are also asked to wait until they are symptom-free before coming in, except in an emergency.

Both measures help to reduce the likelihood of spreading the virus, which can have serious consequences for patients who are already unwell enough to need hospital care.