When we’re anxious, the body produces a stress response. The stress response is designed to give us an extra ‘boost’ of awareness and energy when we think we could be in danger. The stress response causes a number of physiological, psychological, and emotional changes in the body that enhance the body’s ability to deal with a perceived threat – to either fight or flee, which is the reason the stress response is often referred to as the ‘fight or flight response.’
Most of the symptoms of a panic attack are physical, and many times these symptoms are so severe that you may think you’re having a heart attack. In fact, many people suffering from panic attacks make repeated trips to the doctor or the emergency room in an attempt to get treatment for what they believe is a life-threatening medical problem. While it’s important to rule out possible medical causes of symptoms such as chest pain, elevated heart rate, or difficulty breathing, it’s often panic that is overlooked as a potential cause—not the other way around.
The cognitive effects of anxiety may include thoughts about suspected dangers, such as fear of dying. "You may ... fear that the chest pains are a deadly heart attack or that the shooting pains in your head are the result of a tumor or an aneurysm. You feel an intense fear when you think of dying, or you may think of it more often than normal, or can't get it out of your mind."
People with generalized anxiety disorder (GAD) display excessive anxiety or worry, most days for at least 6 months, about a number of things such as personal health, work, social interactions, and everyday routine life circumstances. The fear and anxiety can cause significant problems in areas of their life, such as social interactions, school, and work.