A panic attack is a sudden episode of intense fear that triggers severe physical reactions when there is no real danger or apparent cause. Panic attacks can be very frightening. When panic attacks occur, you might think you're losing control, having a heart attack or even dying.
Many people have just one or two panic attacks in their lifetimes, and the problem goes away, perhaps when a stressful situation ends. But if you've had recurrent, unexpected panic attacks and spent long periods in constant fear of another attack, you may have a condition called panic disorder.
Although panic attacks themselves aren't life-threatening, they can be frightening and significantly affect your quality of life. But treatment can be very effective.