Anxiety, defined by the American Psychological Association (APA), is an emotion characterized by apprehension and bodily symptoms of tension and the anticipation of impending danger. In anxiety disorders, the feelings of fear, dread, and uneasiness are persistent and can be overwhelming. Moreover, the intensity of these feelings can increase over time and interfere with normal daily activities.
Behavior changes such as avoiding previously normal activities
Anxious thoughts or beliefs that are hard to control and do not go away or improve over time.
Pounding or rapid heartbeat
Aches and pains
Shortness of breath
Anxiety is diagnosed with a psychological evaluation performed by a clinician. The psychological evaluation will typically be based on diagnostic criteria set by a publication such as the Diagnostic and Statistical Manual of Mental Disorders (DSM; used in the United States) or the International Statistical Classification of Diseases and Related Health Problems (ICD; used by the World Health Organization).
Antianxiety medications like beta-blockers and antidepressants are commonly used either alone or in conjunction with therapy. Cognitive behavioral therapy (CBT) works well for many anxiety disorders, especially in combination with drugs.
Compared to typically less-healthy diets such as the Western diet, Mediterranean-style and vegan diets have some evidence for their ability to improve mood, although more research is necessary to confirm this.
Some evidence shows that meditation can reduce anxiety symptoms,  particularly among anxious individuals without diagnosed disorders. High-intensity aerobic exercise and resistance training may be effective for treating anxiety disorders. Additionally, binaural beats and cannabidiol have both been studied for anxiety-related outcomes and seem to provide modest benefits.
The causes of anxiety disorders are complex, and risk factors can differ by the type of anxiety (e.g., separation anxiety, generalized anxiety, panic). Genetics, environment, and brain biology can all play a role. Generally speaking, exposure to traumatic or highly stressful events, a family history of anxiety disorders, certain health conditions (e.g., thyroid dysfunction, arrhythmias), and certain personality traits (e.g., excessive shyness) are all associated with an increased risk of having anxiety.