The cause of anxiety disorders is a combination of genetic and environmental factors.[47] Anxiety can stem itself from certain factors: genetics, medicinal side-effects, shortness of oxygen.[48] Risk factors include a history of child abuse, family history of mental disorders, and poverty. Anxiety disorders often occur with other mental disorders, particularly major depressive disorder, personality disorder, and substance use disorder.[49] To be diagnosed symptoms typically need to be present at least six months, be more than would be expected for the situation, and decrease functioning.[10][49] Other problems that may result in similar symptoms including hyperthyroidism, heart disease, caffeine, alcohol, or cannabis use, and withdrawal from certain drugs, among others.[49][7]

To receive a diagnosis of panic disorder, the panic attacks must be unexpected and during the attack four or more of the above symptoms must occur. For panic attacks that are expected, meaning they might not be expected by the individual but are expected in relation to any phobia, anxiety or other mental health disorder, four or more symptoms must also occur.

People with generalized anxiety disorder (GAD) display excessive anxiety or worry, most days for at least 6 months, about a number of things such as personal health, work, social interactions, and everyday routine life circumstances. The fear and anxiety can cause significant problems in areas of their life, such as social interactions, school, and work.