It's the time of year when men are laid low with the dreaded man flu - but is it really as bad as they make out? Medical experts discuss whether men truly suffer as much as they say, or is it simply a case of them making more fuss and wanting to be looked after?
By Lisa Salmon
Bedridden, pale, weak and unable to speak unless asking for something, the man is clearly suffering from a serious condition.
He's got man flu.
An illness that can apparently fell even the most virile, it's also capable of causing serious irritation to female partners and is the source of many sexist jokes.
But while men claim it makes them feel truly awful, many sceptical women insist man flu doesn't actually exist and is in fact nothing more than a cold that they would easily be able to cope with themselves.
So what's the truth behind man flu? Is this debilitating condition real - or are men who get the same respiratory illnesses as women simply less able to deal with them?
Very little research has been specifically directed at the condition. However, some studies have suggested differences in men and women's immune systems that might help explain differences in the way they cope with minor illnesses.
For example, research from Ghent University in Belgium last year found women have a built-in advantage to their immune system linked to them having two X-chromosomes rather than the one that men have.
And a 2009 study from Canada's McGill University showed that the female sex hormone oestrogen boosts women's immune systems.
Professor Ron Eccles, director of Cardiff University's Common Cold Centre, suggests some of the difference in the way men and women react to colds and flu may indeed be related to differences in their immune systems.
Those differences may occur, he says, because when women get pregnant their immune system has to tolerate the 'foreign body' of a growing baby.
"It may be that women are more tolerant of foreign bodies and don't respond as strongly to infection as men, but there's very little scientific data on that, it's just an idea," says Eccles.
He does, however, point out that over their reproductive years, women get significantly more colds than men because of exposure to children, who spread infection.
This raises the possibility that women cope with colds better because they're simply more used to having them.
Aside from possible physical explanations, the difference in men and women's minds is also key, says Eccles.
"Women are different from men psychologically. Maybe men do like to be pampered more, and women like to pamper men.
"There might be something in saying that men react worse to the same illnesses that women get, but men and women both get severe colds and flu, and it's sometimes how they deal with that."
He points out that women's ability to multi-task and get on with things could be a factor, and adds: "Maybe men just love to be pampered - and why not?"
However, while many women will insist that man flu is nothing more than a bad cold, clinical psychologist Roger Kingerlee, who researches men's psychological health, suggests that rather than immediately dismissing a man's malaise, female partners should think about checking if there's a deeper problem.
He points out that men tend to under-report significant symptoms like stress and depression, and says: "If it's true that men over-emphasise cold-related symptoms, it's possible - although it's not going to happen all the time - that guys might be masking issues like stress with something more acceptable like a cold.
"I'm not suggesting celebrating the phenomenon of man flu, but when a man has symptoms it's worth listening to him. It might not be quite what it seems."
While the existence of man flu will always be a source of debate, evolutionary biologist Professor William Amos suggests evolution may provide the answer.
Amos was part of a Cambridge University team which assessed the evolution of male and female immune defences and concluded that men may not be faking illnesses.
He explains that men may have evolved to get rid of an illness as quickly as possible by putting all their energy into fighting it, as opposed to women's more even approach of soldiering on, regardless of how lousy they feel, because they still have to look after the children.
"You might think that both sexes would be pretty equal in terms of how much effort they put into fighting disease, but that's not strictly true," says Amos, who illustrates the difference with the example of red deer.
At the time of the mating rut, if a male deer is ill it could be his last chance gone for a whole season. He may therefore want to put a huge amount of energy into getting rid of disease close to the rut.
On the other hand, a female with offspring will put an even, continuous amount of energy into fighting disease because she can't afford to put everything she's got into the fight as she has to care for her offspring.
"You can draw parallels between what you might expect for animals and what you might expect for humans," says Amos.
He points out that while his Cambridge study wasn't about proving the existence of man flu, it does provide a possible explanation for the way men react to minor illnesses.
"We didn't have huge amounts of evidence that man flu exists, but we were able to say that males might want to get rid of disease quickly and throw all their resources at it, feel lousy and go to bed, but they might be up and ready to compete two days later.
"A woman might have a much more even strategy where she's not out of action for any time, and pushes on instead of trying to get rid of illness quickly.
"Evolution is pretty good at making sure everything's tailored to exactly what you need."
He adds: "Pain and discomfort are so subjective - if a man says he feels awful and he's going to bed, does that really mean he feels bad, or is he just a wimp? It's such a grey area."
However, Dr Clare Gerada, chair of the Royal College of General Practitioners, thinks the evidence is clear.
She says man flu doesn't exist, and while people certainly react in different ways, respiratory tract infections with symptoms including a cough, sore throat, headache, stuffy or runny nose and breathlessness can usually be treated at home by resting, drinking lots of fluid and taking over-the-counter painkillers. If symptoms last longer than two weeks without improvement, a GP should be contacted.
"Contrary to popular belief and, I'm sure, the disappointment of half the population, there is no such thing as man flu," she says.
"Respiratory tract infections are one of the most common problems presented to GPs and pharmacists and they affect people in different ways, with some people reacting more seriously then others."