Anxiety can refer to an invariable and unrealistic worry or fear, about any aspect of everyday life, that can be mild or severe. Everyone experiences feelings of anxiety at some point in their life. For example, an individual may feel worried and anxious about sitting an exam or having a medical test or job interview.

Feeling anxious is sometimes perfectly normal. However, people with generalised anxiety disorder (GAD) find it hard to control their worries. Their feelings of anxiety are more constant and often affect their daily life. GAD is a long-term condition which causes you to feel anxious about a wide range of situations and issues, rather than one specific event. People with GAD feel anxious most days and often struggle to remember the last time they felt relaxed. GAD can cause both psychological (mental) and physical symptoms. These vary from person to person.

There are several conditions for which anxiety is the main symptom. Sleeping problems, restlessness and other possibly physical symptoms; for example, an increased heart beat, stomach upset, muscle tension or feeling shaky may be caused as a result of anxiety. Someone who is highly anxious may also develop related problems, such as panic attacks, a phobia or obsessive compulsive disorder.