I am pretty sure I have only had one panic attack in my life. My chest felt tight; I could hardly breathe; my heart was pounding with palpitations; I was getting tunnel vision along with dizziness - and this is when I was a child. I ran into my mum crying and she managed to calm me down. This was for a few minutes.
Right now, I get what I call "severe anxiety attacks/episodes" - I get extreme anxiety when I don't sleep (and the anxiety is over not sleeping) or when I get hypnic jerks repeatedly (which keeps me awake)! It gets so bad that I feel suicidal every time - not because I feel like I lose purpose or anything but I just want to escape the feeling. The extreme tiredness I get from not sleeping is what amplifies the feeling of anxiety.
I would get these before after having nights of no sleep but I would never worry about not sleeping. I would just spend the day feeling the "derealisation" feeling which also causes irrational thoughts. But now I worry about not sleeping - which makes it worse!
The episodes usually peak for a day (the first day when each one begins) and lingers for about 2-3 days after that but gradually decrease. After those 2-3 days, I may get a good week of feeling ok. Until the odd night, I may be feeling dozy until my body jerks me awake - to which I start panicking - and with every effort to try and control it, I usually fail and the anxiety usually takes over. The first thing I do is get up and start to pace having extremely irrational thoughts. Almost every time I end up in tears (which sometimes helps because when I stop crying I feel a little calmer). I have got up and started to walk outside at 4am in the morning roaming the streets. I sometimes stand on a bridge looking over… feeling extremely frightened that I may jump one day. My anxiety levels at this time usually fluctuate a lot. So in that sense, during an anxiety "episode" I have multiple "attacks".
But when the episodes are over, and the attacks disappear, I am full of energy! I feel motivated, dedicated, and want to do loads of things! My mood is still generally low and my social anxiety and health anxiety still linger - but I have much more rational thoughts than before! I sometimes start to feel confident that I can beat it!
But anyway… that's the nature of my anxiety attacks! And I would call them attacks as well as episodes. I think they are best described as anxiety episodes consisting of anxiety attacks. But they are never like the experience I had when I was a child. Because I literally felt like I was dying - and that's my understanding of a "panic attack"!