A panic attack is an abrupt surge of intense fear or discomfort that reaches a peak within minutes, and during which time a variety of psychological and physical symptoms occur. These symptoms include rapid heart rate, sweating, shaking, shortness of breath, hot flashes, and lightheadedness—as well as a sense of impending doom, chills, nausea, abdominal pain, chest pain, headache, and numbness or tingling.
When we experience an involuntary high degree stress response, the sensations can be so profound that we think we are having a medical emergency, which anxious personalities can react to with more fear. And when we become more afraid, the body is going to produce another stress response, which causes more changes, which we can react to with more fear, and so on.
So I can tell you that panic attacks aren't dangerous, but I recognize that this is "easy for me to say". If you're having anxiety attacks, especially if they're a relatively new occurrence for you, you might not be able to believe this right now. That's entirely understandable when you feel that your life is threatened! You don't need to take anything here on faith. Instead, check it all out. Test everything I say against your own experience, as you work your way through this site.
Separation anxiety disorder: Separation anxiety is often thought of as something that only children deal with; however, adults can also be diagnosed with separation anxiety disorder. People who have separation anxiety disorder have fears about being parted from people to whom they are attached. They often worry that some sort of harm or something untoward will happen to their attachment figures while they are separated. This fear leads them to avoid being separated from their attachment figures and to avoid being alone. People with separation anxiety may have nightmares about being separated from attachment figures or experience physical symptoms when separation occurs or is anticipated.