Panic attack is very hard to describe, but has a unique symptom: the feeling of impending doom.

Everything about you is telling you something is very fucking wrong right now and you're about to perish. Your survival instinct kicks in, fight or flight, heart races, chest feels tight, tunnel vision, you sweat and hyperventilate. You basically are having the sensation of a heart attack or something equally catastrophic, but nothing is actually going on.

It is the most terrifying thing that can happen to you. The first 5 times are hell, then you learn that it tends to be relatively short lived, even if it feels like eternity. What I do is take my phone out and look at the time. Come hell or high water, in 20 minutes I will be fine. Relief often is sudden, but there's times you stay in a state of sub-panic for longer than that.

Truth be told, full blown panic attacks are, even for a very anxious person as I was, rare (and twice so unbearable I called emergency services), the vast majority I call anxiety attacks which are a little milder version of oh fuck I'm going to die now.

I'll attempt an answer: it's your flight-or-flight response kicking in, without any obvious reason for it to do so. Oxygen intake goes up, muscles tense up, adrenaline production kicks in, but there's nothing for your body to "spend" these physiological changes on (like running for your life), so it just sloshes around causing panic attack symptoms (eg sweating, trembling, shortness of breath, chest pain, nausea, detachment, fear of dying).

In my twenties I had some years of severe panic attacks. It is funny, it completely dominated my life but I totally forgotten about it. Feel writing it off my chest, maybe it can help somebody.

For me they were hypochondria related. My vision would turn black, my heart would start racing and I got the feeling that ants where crawling from my heart to my arm. At these moments I was convinced I was dying of a heart attack or some artery was torn from my heart. Doctors would find nothing wrong with me, this increased my fear because it meant I couldn't receive any help. They attacks could last for hours, making me unable to sleep and mentally depleting me.

I have actually been close to death a couple of times for real. Once falling through the ice and once having a rare disease. These moments did not feel the same. Actually I was rather calm in these moments.

They attacks made such an impact on me that after a while I started being mortally afraid of having a panic attack. Thinking about it, thinking about my body, feeling the slightest discomfort in my body all these things would trigger another attack. Because of that I lost touch with my body. Worse thing was that I would sometimes wake up in the middle of an attack. This made me afraid of falling asleep. I would walk or cycle at night because I was too afraid to sleep. This made things much worse.

At one point I mentally saw the vicious circle I created for my self. I remember seeing it as one of those smoke circles some people make while smoking. I saw that my focus on this was what kept that circle alive. I saw that I simply had to stop identifying with it, step away from it. Almost magically the attacks have never returned.

The “I’m going to die” variety of panic attack is only one of many. Other people have them when driving on the highway, just stepping outside their door or meeting too many people at the same time.

There’s generally a more direct trigger than watching TV, but sure, see the wrong show, think the slightly wrong thought, notice that little bulge on the left side of your big toe when you’ve propped them up on the table. Take a few more cycles of things you worry about and you’re well and truly in the middle of a panic attack (which is as described in another comment).

The nasty part is that it’s hard to recognize as such when you’re in the middle of it.

Unfortunately it can have the same symptoms as a real heart attack or stroke. Tightness and pain in the chest. A feeling of dizziness. Visual things like not being able to focus or darkness around the edges. For me the most pronounced thing is a crawling sensation under the skin of my head and down my face and the weird feeling that something is sticking out the side of my head. And yea, the intrusive thought that you're going to die, which your brain seems to rationalize with a bunch of stupid reasons.

You can also hyperventilate and not really notice it in your breathing. That makes your hands curl up by themselves and then pins and needles. I only got that once, after that I learnt some breathing exercises.

It feels like when you're on a plane and it suddenly drops due to turbulence without warning. Only you could be anywhere doing anything.

I think Panic Attack is overused just to mean someone is uncomfortable with a situation they're in or they're hyperventilating, but I think I had one several years ago but I'm open to being corrected.

I was driving from LA to OC every day which is probably 3+ hours of driving normally working for a client that was an absolute ass. I was working 9 "real" hours a day meaning I didn't even have time to click around on the internet like most jobs I've had since. I was having issues with my prostate hurting in my mid-20s (turns out it was a lifting belt for squats) and I had just moved to a new city.

After 9 months, I was about halfway home where my prostate started hurting again and I just got tunnel vision where I couldn't see ANYTHING. It looked like I could only see a pin of light in each of my eyes and my ears felt like they were under water. I was in the left lane and I couldn't see for shit so I just said a quick prayer and swerved 3 lanes over to the shoulder when I promptly passed out and came to about 5-10 minutes later. I found a new job a month later and said fuck it to driving that much ever again.

I should say that this has only happened once and that I'm very very happy and confident with my life 99% of the time. I've never experienced anything like this before or after and I assume it was a panic attack.

For people who are curious about my prostate problems, I went to several urologists and no one could find anything after several uncomfortable examinations. I decided to try to scientific method and finally removed my lifting belt from use for a few weeks and the pain has been gone since. I figured it was related to my pelvic floor muscles and how they bunched up during a really tight belt/squat session doing pretty heavy weights (365-405) pretty frequently.