Most people experience feelings of anxiety before an important event such as a big exam, business presentation or first date. Anxiety disorders, however, are illnesses that cause people to feel frightened, distressed and uneasy for no apparent reason. Left untreated, these disorders can dramatically reduce productivity and significantly diminish an individual's quality of life.
Furthermore, certain organic diseases may present with anxiety or symptoms that mimic anxiety.[6][7] These disorders include certain endocrine diseases (hypo- and hyperthyroidism, hyperprolactinemia),[7][73] metabolic disorders (diabetes),[7][74][75] deficiency states (low levels of vitamin D, B2, B12, folic acid),[7] gastrointestinal diseases (celiac disease, non-celiac gluten sensitivity, inflammatory bowel disease),[76][77][78] heart diseases, blood diseases (anemia),[7] cerebral vascular accidents (transient ischemic attack, stroke),[7] and brain degenerative diseases (Parkinson's disease, dementia, multiple sclerosis, Huntington's disease), among others.[7][79][80][81]
Humor and laughter, in addition to being fun and enjoyable, have many health benefits. Laughter can help people cope with stress, reduce anxiety and tension and serve as a coping mechanism. Humor may allow a person to feel in control of a situation and make it seem more manageable. By helping to reduce fear, anger and stress, humor can help minimize the potential harm they can have on the body over time.
Obsessive-compulsive and related disorders are characterized by obsessive, intrusive thoughts (e.g. constantly worrying about staying clean, or about one's body size) that trigger related, compulsive behaviors (e.g. repeated hand-washing, or excessive exercise). These behaviors are performed to alleviate the anxiety associated with the obsessive thoughts. These types of disorders can restrict participation in everyday life and/or generate significant distress, for instance, by making it difficult to leave the house without many repetitions of a compulsive behavior (e.g. checking that the doors are locked). Periodically experiencing worry or having a few "idiosyncratic" habits does not constitute an obsessive-compulsive or related disorder. Instead, these disorders are characterized by unusually high levels of worry and related compulsive behaviors, in comparison with a typical range of individuals.
People with panic disorder often worry about when the next attack will happen and actively try to prevent future attacks by avoiding places, situations, or behaviors they associate with panic attacks. Worry about panic attacks, and the effort spent trying to avoid attacks, cause significant problems in various areas of the person’s life, including the development of agoraphobia (see below).