Centre for Addiction and Mental Health, Toronto
http://www.camh.net/About_Addiction_Mental_Health/Mental_Health_Information/Anxiety_Disorders/anxiety_anxiety_disorders.html
(Please note: This information comes directly from the CAMH site verbatim)
What is normal anxiety?
A certain amount of anxiety is normal and necessary; it can lead you to act on your concerns and protect you from harm. In some situations, anxiety can even be essential to your survival. If you were standing at the edge of a curb, for example, and a car swerved toward you, you would immediately perceive danger, feel alarm and jump back to avoid the car. This normal anxiety response, called the “fight or flight” response, is what prompts you to either fight or flee from danger.
When we feel danger, or think that danger is about to occur, the brain sends a message to the nervous system, which responds by releasing adrenaline. Increased adrenaline causes us to feel alert and energetic, and gives us a spurt of strength, preparing us to attack (fight) or escape to safety (flight). Increased adrenaline can also have unpleasant side-effects. These can include feeling nervous, tense, dizzy, sweaty, shaky or breathless. Such effects can be disturbing, but they are not harmful to the body and generally do not last long.
How does anxiety affect us?
Wenever the fight or flight response is activated by danger, either real or imagined, it leads to changes in three “systems of functioning”: the way you think (cognitive), the way your body feels and works (physical), and the way you act (behavioural). How much these three systems change varies, depending on the person and the context.
- cognitive: Attention shifts immediately and automatically to the potential threat. The effect on a person’s thinking can range from mild worry to extreme terror.
- physical: Effects include heart palpitations or increased heart rate, shallow breathing, trembling or shaking, sweating, dizziness or lightheadedness, feeling “weak in the knees,” freezing, muscle tension, shortness of breath and nausea.
- behavioural: People engage in certain behaviours and refrain from others as a way to protect themselves from anxiety (e.g., taking self-defence classes or avoiding certain streets after dark).
It is important to recognize that the cognitive, physical and behavioural response systems of anxiety often change together. For instance, if you are spending a lot of time worrying about your finances (cognitive), you are likely to feel physically on edge and nervous (physical), and may spend quite a bit of time checking your household budget and investments (behavioural). Or if you’re preparing for an important exam, you may worry about doing your best (cognitive), feel tense and maybe even have “butterflies” (physical), and initially avoid studying and then cram at the last minute (behavioural).
The key points to remember about anxiety are that it is:
- normal and experienced by every living organism
- necessary for survival and adaptation
- not harmful or dangerous
- typically short-lived
- sometimes useful for performance (at low or moderate levels).
When is anxiety a problem?
Everyone experiences symptoms of anxiety, but they are generally occasional and short-lived, and do not cause problems. But when the cognitive, physical and behavioural symptoms of anxiety are persistent and severe, and anxiety causes distress in a person’s life to the point that it negatively affects his or her ability to work or study, socialize and manage daily tasks, it may be beyond normal range.
The following examples of anxiety symptoms may indicate an anxiety disorder:
- cognitive: anxious thoughts (e.g., “I’m losing control”), anxious predictions (e.g., “I’m going to fumble my words and humiliate myself”) and anxious beliefs (e.g., “Only weak people get anxious”).
- physical: excessive physical reactions relative to the context (e.g., heart racing and feeling short of breath in response to being at the mall). The physical symptoms of anxiety may be mistaken for symptoms of a physical illness, such as a heart attack.
- behavioural: avoidance of feared situations (e.g., driving), avoidance of activities that elicit sensations similar to those experienced when anxious (e.g., exercise), subtle avoidances (behaviours that aim to distract the person, e.g., talking more during periods of anxiety) and safety behaviours (habits to minimize anxiety and feel “safer,” e.g., always having a cell phone on hand to call for help).
Several factors determine whether the anxiety warrants the attention of mental health professionals, including:
- the degree of distress caused by the anxiety symptoms
- the level of effect the anxiety symptoms have on a person’s ability to work or study, socialize and manage daily tasks
- the context in which the anxiety occurs.