Anxiety disorder is a general term that refers to many types of mental illness involving abnormal, pathological anxieties and fears. Anxiety disorders fall under one of two categories: continuous symptoms (those that are always present in the patient and never leave) and episodic symptoms (those that come and go, and may or may not have specific triggers). There are at least six kinds of disorders that can fall under the general term of “anxiety disorder”:

• Generalized anxiety disorder. A common disorder in which a person has long-lasting anxiety that is not focused on any particular situation or object. Patients have non-specific fears and worries and obsess over everyday matters.

• Panic disorder (with agoraphobia). Panic disorder causes what are often known as “panic attacks”, where a person undergoes a brief attack of intense apprehension or terror, with the possibility of confusion, shaking, nausea, and breathing trouble. These may sometimes lead the person to avoid any situations that may trigger a panic attack, perhaps preventing them from rarely or ever leave their homes.

• Phobias. The most common form of anxiety disorder, phobias is characterized by an intense, irrational fear triggered by a specific situation, object, or stimulus, with the sufferer expecting terrifying consequences upon encountering the subject of their phobia.

• Obsessive-compulsive disorder (OCD). Characterized by repetitive compulsions (strong urges to perform certain acts in a ritualistic manner, such as cleaning or hoarding) and obsessions (a preoccupation with intrusive thoughts or images), with the former often being used as a way to relieve the stress of the latter.

• Post-traumatic stress disorder (PTSD). PTSD is an anxiety disorder that results from a traumatic experience, such as combat, hostage situations, child abuse, or serious accidents. This includes long-term stressors, such as soldiers who are unaffected by a single battle but cannot withstand the mental stress of continuous combat engagements.

• Separation anxiety. An inappropriate and excessive level of anxiety caused by being separated from a certain person or place. It is most common in infants and young children.

Treatment of an anxiety disorder varies depending on the specific disorder being treated, as well as the severity of the disorder and how quickly and accurately it was diagnosed. Many techniques are used to treat anxiety disorders, including (sometimes monitored) self-help, psychotherapy, and various medications.