Olivia admits she’s always been a worrier – but when she started university, her anxiety steadily began to build. One day she was simply too frightened to leave the house. For two weeks she was stuck indoors, before she was diagnosed with generalised anxiety disorder and began to get the help she needed.  With support from her GP and university wellbeing service, and courses of cognitive behavioural therapy (CBT), she was able to stick with her university course and to start enjoying life again.  But Olivia is far from alone in her anxiety: the number of students declaring a mental health problem has doubled in the last five years, to at least 115,000.  “And that is a very small proportion of the students who are having mental health difficulties,” says Ruth Caleb, chair of Universities UK’s mental wellbeing working group.  Related: Want to learn faster? Stop multitasking and start daydreaming  A study of UK undergraduates has found that even among students symptom-free before starting university, some 20% are troubled by a clinically significant level of anxiety by the middle of second year.  What does anxiety do to students? It causes the body to prepare itself for fight or flight.  “If you are in a situation of imminent actual threat, then the increased alertness and body response can be lifesaving,” explains Chris Williams, professor of psychosocial psychiatry at the University of Glasgow, and medical advisor to Anxiety UK.  “But if it occurs when trying to revise, or present a talk, or at such a high level that it paralyses or causes errors, it can interfere with what we want to do.”  What happens in the brain of someone experiencing excessive anxiety is not fully understood. One line of research, says consultant psychiatrist Rajeev Krishnadas, is that it involves the prefrontal cortex and the amygdala – a key region of the brain involved in learning and memory, as well as in the physiological and behavioural responses to fear.  “An external stimulus – sight, hearing, touch, smell and taste – activates a number of regions of the brain, crucially including the amygdala,” says Krishnadas. Under normal circumstances, he says “the amygdala is under tight control from the prefrontal cortex, which evaluates the threat associated with the stimulus. If the stimulus is non-threatening, the activity within the amygdala is suppressed. If it is threatening, the amygdala fear response is maintained.”  In someone with an anxiety problem, it seems, the brain is making incorrect decisions about what to fear and the prefrontal cortex fails to suppress the amygdala, putting the body into fight or flight mode.  Related: How much can you really learn while you're asleep?  In this state, levels of the hormone adrenaline rise and the sympathetic nervous system – which controls automatic activities (like breathing) rather than conscious action – takes over. The heart rate rises, breathing speeds up and blood is diverted to the limbs, blood pressure and body temperature increase, and you may start to sweat.  This is clearly not a state conducive to learning or concentrating in a seminar, says clinical psychologist Dr Angharad Rudkin. “Even if you manage to take in what is being said, the information is likely to bounce around [in your brain], not being processed properly or stored in your long-term memory.”  Last month, Anxiety UK launched a student guide to anxiety. Here are Anxiety UK and Dr Rudkin’s top 10 self-help tips:  Further information and support is also available from Student Minds, Young Minds and Nightline.  Get involved with the Use your head series by joining the discussion on #useyourhead or pitching your ideas to natalie.gil.casual@theguardian.com  Keep up with the latest on Guardian Students: follow us on Twitter at @GdnStudents – and become a member to receive exclusive benefits and our weekly newsletter.
Levels of stress and anxiety are on the rise among students. Juliet Rix has tips to control the panic and thrive academically