So, what seems to be the problem?

Cold, flu, the norovirus, – you name it really. It's that time of year when illness abounds, wiping out whole departments and bringing even the most dedicated employees to their knees.

That sounds familiar – the guy who sits next to me has a desk littered with tissues and he stinks of Lemsip. Shouldn't he be at home?

Quite possibly. According to Cary Cooper, professor of organisational psychology and health at Lancaster University, there is an "epidemic of job insecurity", a symptom of which is people struggling into work when they should be off. "With jobs being cut, people feel they have to show face time," he says. "Also, there are fewer people than there were doing the work."

As well as those who keep soldiering on, Cooper suggests that rather than risk being badged a skiver, some people come in to demonstrate they are genuinely sick, but are quite relieved when they are eventually told to go home.

So should I tell my colleague to pack his bags and take his germs home?

You could gently nudge him in that direction, says Cooper. After all, he might make the rest of you sick if he keeps coughing through meetings. Dr Jenny Leeser, clinical director, occupational health at Bupa, puts it bluntly: "They're not going to be effective and they are going to spread it around."

If you're the boss, you should take matters in hand. "Reassure him that everything is OK – you know he's ill, that there's no problem and just send him home," says Cooper.

This is assuming your colleague is in a fit condition to get home under his or her own steam. If someone is looking peaky, but it is not an emergency, "as a caring employer you may be inclined to say 'take a taxi'", says Leeser.

This is all well and good, but the woman I'm working with on a project is off because her children have chickenpox

Well be grateful your colleague hasn't brought chickenpox into the office – it's a nasty thing for adults to catch and dangerous to unborn children, so pregnant colleagues won't want to catch it. "We get lots of queries from parents whose children have chickenpox," says Leeser. "If people are fairly sure they haven't had it before then they shouldn't be in work as they could be incubating it." Leeser suggests that someone in this situation might be able to work from home, so you may still be able to get your colleague to help.

What about all the rest of the work?

"Managers need to be aware of the impact that staff sickness – especially if a large number of people are off at the same time or one person is out for a prolonged period – will have on those colleagues left in the factory or office," says Hugh Robertson from the TUC. "The additional workload falling on colleagues must be managed, so employees feel able to speak out if they are concerned that their workload is becoming excessive." As Robertson points out, causing those who are well to panic because they have too much to do is not in anyone's interest and could lead to more absence.

If you're the boss, Cooper says it is helpful "to create a kind of team spirit" – bring those who work with the absent colleague together and tell them that you all need to pull together to cover the workload. Although this is easier if the colleague is popular.

I'm feeling a bit pale myself now, what if I don't feel well tomorrow?

Stay at home. "Rather than 'mucus-trooping' into work, poorly workers would be better off resting and getting well before making their return to the office," says Robertson.

And if the thought of "mucus-trooping" hasn't turned your stomach, you're definitely well enough to be at your desk.