Anxiety is a feeling of nervousness, apprehension, fear, or worry. It is considered to be a normal reaction to a stressor. When anxiety becomes excessive, it may fall under the classification of an anxiety disorder. It is a multisystem response to a perceived threat or danger. It reflects a combination of biochemical changes in the body, the patient's personal history and memory, and the social situation.
Generalized Anxiety Disorder (GAD) is a chronic disorder characterized by excessive, long-lasting anxiety and worry about nonspecific life events, objects, and situations.
GAD sufferers often feel afraid and worry about health, money, family, work, or school, but they have trouble both identifying the specific fear and controlling the worries. Their fear is usually unrealistic or out of proportion with what may be expected in their situation. Sufferers expect failure and disaster to the point that it interferes with daily functions like work, school, social activities, and relationships.
Biological. Stress. Stress at work. Stress from school. Stress in a personal relationship such as marriage or friendships. Financial stress. Stress from an emotional trauma such as the death of a loved one, a natural disaster, victimization by crime, physical abuse or sexual abuse (for example, acute stress disorder or post traumatic stress disorder) Stress from a serious medical illness. Side effects of medication. Intoxication (being "high" on) with an illicit drug, such as cocaine or amphetamines Withdrawal from an illicit drug, such as opiates (for example, heroin) or from prescription drugs like benzodiazepines, barbiturates etc. Symptoms of a medical illness. Lack of oxygen: In circumstances as diverse as high altitude sickness, emphysema etc.