A panic attack is a sudden, overwhelming feeling of fear and/or extreme anxiety, that may or may not have a clear cause. In a panic attack you often feel so frightened that you become incapable of doing anything; people typically feel unable to breathe properly, get dizzy and often feel sick. The first sign of an attack is often a very fast heartbeat, followed by feelings of extreme heat or cold, and sweating.

Many, perhaps most people have a panic attack at some point, and usually the feeling goes away after a few minutes. If you have such feelings often, for example once a month or more, you may be suffering from panic disorder. People who feel very anxious a lot of the time are prone to have occasional full blown attacks, which are very frightening and upsetting even though they normally don't physically harm you.

It's sometimes possible to get help if you have repeated panic attacks. You can find a full list of symptoms, as well as links to treatment and self-help options (on the tabs above the main article.)