These episodes are a serious health problem in the U.S. At least 20% of adult Americans, or about 60 million people, will suffer from panic at some point in their lives. About 1.7% of adult Americans, or about 3 million people, will have full-blown panic disorder at some time in their lives, women twice as often as men. The most common age at which people have their first panic attack (onset) is between 15 and 19 years of age. Panic attacks are significantly different from other types of anxiety, in that panic attacks are very sudden and often unexpected, appear to be unprovoked, and are often disabling.
When people are confronted with unpleasant and potentially harmful stimuli such as foul odors or tastes, PET-scans show increased bloodflow in the amygdala.[87][88] In these studies, the participants also reported moderate anxiety. This might indicate that anxiety is a protective mechanism designed to prevent the organism from engaging in potentially harmful behaviors.

Researchers have conducted both animal and human studies to pinpoint the particular parts of the brain that are involved in anxiety and fear. Because fear evolved to deal with danger, it sets off an immediate protective response without conscious thought. This fear response is believed to be coordinated by the amygdala, a structure deep inside the brain. Although relatively small, the amygdala is quite complex, and recent studies suggest that anxiety disorders may be associated with abnormal activity within it.
Anxiety is typified by exaggerated worries and expectations of negative outcomes in unknown situations, and such concerns are often accompanied by physical symptoms. These include muscle tension, headaches, stomach cramps, and frequent urination. Behavioral therapies, with or without medication to control symptoms, have proved highly effective against anxiety, especially in children.
Fear and anxiety are part of life. You may feel anxious before you take a test or walk down a dark street. This kind of anxiety is useful - it can make you more alert or careful. It usually ends soon after you are out of the situation that caused it. But for millions of people in the United States, the anxiety does not go away, and gets worse over time. They may have chest pains or nightmares. They may even be afraid to leave home. These people have anxiety disorders. Types include
Family Therapy is a type of group therapy that includes the patient's family to help them improve communication and develop better skills for solving conflicts. This therapy is useful if the family is contributing to the patient's anxiety. During this short-term therapy, the patient's family learns how not to make the anxiety symptoms worse and to better understand the patient. The length of treatment varies depending on the severity of symptoms.

People with panic attacks often report a fear of dying or heart attack, flashing vision, faintness or nausea, numbness throughout the body, heavy breathing and hyperventilation, or loss of body control. Some people also suffer from tunnel vision, mostly due to blood flow leaving the head to more critical parts of the body in defense. These feelings may provoke a strong urge to escape or flee the place where the attack began (a consequence of the "fight-or-flight response", in which the hormone causing this response is released in significant amounts). This response floods the body with hormones, particularly epinephrine (adrenaline), which aid it in defending against harm.[9]
Medication does not cure anxiety disorders but can help relieve symptoms. Medication for anxiety is prescribed by doctors, such as a psychiatrist or primary care provider. Some states also allow psychologists who have received specialized training to prescribe psychiatric medications. The most common classes of medications used to combat anxiety disorders are anti-anxiety drugs (such as benzodiazepines), antidepressants, and beta-blockers.