Can you keep your eyes open long enough to read this feature? We won’t be offended if you can’t. The Royal College of Psychiatrists says that one in five of us feels unusually tired at any one time, and one in ten feels permanently fatigued. Tiredness and fatigue are behind 20 per cent of UK doctor consultations, according to a recent survey of GPs. No wonder doctors are regularly jotting down a handy new acronym – TATT (Tired All The Time) – in patient notes. Or that UK sales of energy drinks shot up by 155 per cent between 2006 and 2014. We are, it seems, an exhausted nation.
Tiredness is no joke. Sleep deprivation brings a heavy mental and physical toll. Around 20 per cent of accidents on major roads are sleep-related, according to the Department of Transport. Plus, people who are sleep-deprived lose the ability to be positive-minded, which researchers from the University of Pennsylvania say is likely to increase the likelihood of depression. There’s also evidence that sleep deprivation increases the risk of obesity, heart disease, diabetes and stroke.
Even if you’re getting enough sleep, feeling constantly fatigued can be bad for you. Research from the University of Alabama has found that working hard while fatigued increases blood pressure. This is because tired people increase their effort to make up for their diminished capability when they want to accomplish a task.
For those with conditions such as chronic fatigue syndrome (CFS/ME) and cancer, it severely restricts quality of life. For millions of others, unexplained tiredness regularly rumbles in the background. Is there something wrong with us? Are we the victims of hectic 24-hour lifestyles? Why are we tired all the time?
Until now, little has been known about the biological processes that result in what we call tiredness or fatigue. Only in recent decades, with growing concern about the prevalence of conditions such as CFS/ME, has research money been invested into the causes of long-term fatigue. And it is becoming clear that, although there is a wide spectrum of tiredness types, they are all linked and their causes interact.
Prof Julia Newton, director of the Newcastle Centre for Fatigue Research at Newcastle University, explains the causes of tiredness via a classic bell-shaped curve graph. “At the thin end of the curve, there are people who just need to get some sleep and get their lifestyle in order. At the other thin end of the curve there are clearly people who have diagnosed or undiagnosed illness that is causing fatigue. And then, there’s everything else in the wide middle part of curve.”
The wide middle is the complex bit, covering tiredness caused by combinations of many environmental, lifestyle and health factors. And recent research is beginning to reveal how genetics, cell function, inflammation and the brain’s response to light may all have an underlying role in this tiredness ‘mainstream’.
At a cellular level, scientists are increasingly looking at the role of mitochondria – the power packs in every human…
This is an extract from issue 313 of BBC Focus magazine. To read the rest of this article pick up a copy at all good newsagents, download the BBC Focus app or subscribe and get the latest issue delivered straight to your door.