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14th Jan 2024

‘Never-ending’ cold explained by scientists amid rise of ‘100 day cough’

Charlie Herbert

There are a whole host of reasons you could be experiencing what feels like a ‘never-ending’ cold.

As everyone returns to work and school following the festive period, coughs and colds have once again reared their ugly heads.

And it seems that many people are struggling to kick the symptoms, complaining of a ‘never-ending’ cold. At the same time, some are reporting suffering from a ‘100-day cough.’

Meanwhile, the number of flu patients in hospitals in England is at more than 1,300, and the number of patients testing positive for COVID-19 has increased for the fifth week running.

Now, experts have given some explanation as to why people may be suffering from prolonged illness and symptoms this winter.

Ron Eccles, an emeritus biosciences professor at Cardiff University, and the former director of its Common Cold Centre, explained that one of the main reasons colds and viruses surge after Christmas is children returning to school.

He told WalesOnline: “There are also more colds in winter, and the wet weather has kept us indoors and the damp has helped viruses survive better.”

“There are complaints about never-ending colds, and this may be due to multiple infections, or us being more rundown and stressed at this time of year after festive excess.”

The advice if you’re ill is nothing new: keep away from people who may be more vulnerable to illness, such as the elderly, as this could cause more serious disease.

But is there any truth in the theory that colds are sticking around for longer?

One reason your cold symptoms could be hanging around is because of something called postnasal drip.

Dr Marwan Azar, an infectious diseases physician at Yale Medicine, told HuffPost: “If you have ongoing cold symptoms, such as a recurring cough or an irritated throat for longer than two weeks, it’s generally not because of a persistent infection but due to consequences of lingering inflammation from a cleared infection, specifically postnasal drip.”

Postnasal drip is when your body produces mucus in your sinuses and nasal cavities, which then drips down the back of your throat. This is usually what causes the tickle that makes you cough.

Because it takes time for your immune system to get rid of all the mucus, the congestion can hang around for up to a week after you’ve actually gotten rid of the cold virus from your system.

And research from Queen Mary University London has found some evidence of ‘long colds’ being a thing. Their study found the most common symptoms of the ‘long cold’ are coughing, stomach pain and diarrhoea more than four weeks after initial infection.

The main factor in how long symptoms hang around is usually the severity of the infection, but the research said more work needs to be done to establish why some people suffer more than others.

The COVID-19 pandemic may also have prompted an increase in viral infections this winter, but not because of COVID-19 infections themselves. Jeremy Brown, a professor of respiratory infection at University College London explained there has been a “bounce-back with frequency of infection with some respiratory viruses” due to “lack of exposure to respiratory viruses weakening adaptive immunity to the viruses.”

This theory was echoed by GP Dr Alisha Esmail who spoke of a ‘post-covid effect.’

She said: “We had less exposure to the classical winter viruses due to quarantining and isolating, and so we’re catching up now on rebuilding our immune responses.

“Remember, viruses mutate and immune responses fade over time. Our individual immunity also has a huge number of factors – some within and some beyond our control.”

So, what about this 100-day cough then? Well, this is thought to be cases of whooping cough, which you’re likely to have heard of particularly if you’re a parent.

This bacterial infection affects the patient’s lungs and throat, meaning that infant vaccination against it is absolutely imperative.

From early July to the end of November last year, there were 716 suspected cases of whooping cough in England and Wales, up from 217 in the same period in 2022, the Guardian reports.

The five main symptoms of whooping cough are:

  • Coughing bouts lasting for a few minutes and are worse at night
  • Coughs that make a “whoop” sound – a gasp for breath between coughs
  • Difficulty breathing after coughs, which could lead to turning blue or grey in young infants
  • Bringing up a thick mucus, which can lead to vomiting
  • Turning very red in the face
  • These signs and symptoms can take seven to 10 days to show and are usually mild at first, meaning they can often be mistaken for a common cold.

The rise is thought to be down to a drop in vaccination rates.

A typical cold usually lasts between seven and 10 days, but if symptoms persist beyond three weeks, worsen suddenly, or you have a high fever or breathing difficulties, you should probably visit your GP.

“Resting, keeping well-hydrated and using over-the-counter treatments could shorten its stay, but if you’re still sniffling after three weeks, it’s time to take some action,” Dr Esmail advised.

(This article was originally published on and is republished here with permission.)

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