Do you have flu fatigue?

This is the time of year when many of us feel depleted, pushing on doggedly despite suffering repeated bouts of colds and possibly even flu. We dismiss our poor mood and cognitive impairments as signs of weakness, of our inability to cope.

But could these symptoms be manifestations of the illnesses themselves? And even if they’re not, wouldn’t it be better to look for ways to feel better, instead of blaming ourselves and lowering self-esteem still further?

Infectious diseases such as colds and flu have a real effect on cognitive functioning. Lucile Capuron and colleagues at the Neurobiological Laboratory in Bordeaux, France, tested memory and attention processes in 91 adults.

Thirty of them were healthy at the time of testing, 29 were suffering from flu-like symptoms including fever and 32 had flu-like symptoms but no fever. Compared to healthy participants, those with flu performed less well on all the tests, particularly those that required them to manage larger amounts of information.

Andrew Smith and colleagues at the University of Bristol studied the effects of having a cold on both mood and cognitive processes. Compared to healthy controls, participants with colds showed impaired tracking abilities and reaction times, and scored less well on attention tasks — although their memory wasn’t affected. Those with colds also had lower mood.

When you’re exposed to infection, your body’s reaction is to activate your immune system. This activation, necessary to fight the invading bacteria or virus, causes cellular inflammation. Some researchers think there may be an association between such inflammation and depressive symptoms such as poor mood, fatigue and lack of motivation.

It’s understandable to feel depressed when you’re ill, even if there is no physical basis.

But whatever the cause, it’s a good idea to heed your body’s warning to slow down so your immune system can fight the infection effectively.