Anxiety disorder is a far more common problem than was once thought. It can affect people in their teenage years through middle age and later. Anxiety disorder can be either acute or chronic. Acute anxiety disorder manifests itself in episodes commonly known as panic attacks. This is a complex, involuntary physiological response in which the body prepares itself to deal with an emergency situation.
Stress causes the body to produce more adrenal hormones, especially adrenaline.
The increased production of adrenaline causes the body to step up its metabolism of proteins, fats, and carbohydrates to quickly produce energy for the body to use. In addition, the muscles tense, and heartbeat and breathing become more rapid. Even the composition of the blood changes slightly, to make it more prone to clotting. In the face of a threat such as an assault, an accident, or a natural disaster, this type of reaction is perfectly normal and helpful for survival. At other times, the symptoms caused by a surge in adrenaline can be distressing and frightening.