The mechanism of panic attacks is interesting. In summary, what happens is that the sufferer's basal blood carbon dioxide level drops too low, which causes their body to produce a massive surge of adrenaline in response. As adrenaline is the "fight or flight" hormone, getting a massive surge of it out of nowhere and for no (apparent/conscious) reason makes you start to panic. So if you're not able to shut off the part of your brain that starts squeaking "oh my god we're[*] dying" by telling it "no, it's just panic, we're[*] ok", you then have a panic attack.
Most people have panic attacks caused by disturbed psychology. Being anxious for a long period of time increases your breathing rate imperceptibly, causing the basal carbon dioxide level to slowly decrease. Just a tiny change from the normal 10-15 breaths/minute at rest to 15-20 breaths/minute is enough to cause the CO2 disturbance. The surge of adrenaline kicks in when the level drops below a certain threshold. The most interesting thing about it is that it's a vicious spiral - there is so much feedback in the process that every iteration gets worse. Being anxious increases your likelihood of hyperventilating, which increases your chance of having the adrenaline surge, which increases your chance of having a panic attack, which increases your baseline anxiety level. Rinse, repeat. This is the well-known phenomenon that "panic breeds panic". It's also why someone with PTSD, faced with the situation that is most triggering for them, might be absolutely fine while it's happening - then come home, collapse in a chair with beverage of choice and have a panic attack then. Because while they were hyperventilating during the stressful event, their blood carbon dioxide level was still ok - but the sigh of relief as they sat down at home was enough to drop their CO2 level below that threshold point.
My panic attack this morning had the cause and effect reversed compared to how most people have them. While for most people it's the broken psychology that triggers the physiological response of hyperventilation, with me it's far more likely that the physiological problem of hyperventilating provokes the broken bits of my brain. My hyperventilation has three main factors:
1) Having had untreated asthma for years which then became treated by giving me an inhaler. 50 years ago, before we had effective drugs, it was normal to give asthmatics physiotherapy to teach them how to use their lungs and the various muscles involved in ventilation properly - but the first time anyone ever watched me breathe and showed me which muscles I was supposed to use was March 2003. It's rather difficult to learn how to breathe aged 26.
2) While I did a load of breathing retraining a few years ago, it's still not "natural" for me to breathe using my diaphragm. This is especially a problem when doing a lot of talking, because talking makes you exhale a lot of air. Chronic hyperventilators then start to panic, feeling that they're running out of air, and gulp down air inbetween words using the accessory muscles in the top of the chest, instead of pausing and taking a deep breath using the diaphragm. Thus the more talking I do, the more likely I am to not breathe properly - and as my job involves vast quantities of talking, the more overworked I get, the more likely I am to make myself exhausted. Yay!
3) While factors (1) & (2) are "sort of" under my control, another of my problems is a whole collection of respiratory allergies, which have a tendency to cause my nose to block up. This means that, despite my best efforts of breathing carefully while awake, I often wake up with my nose so blocked it takes several squirts of saline before I can even blow all the gunk out, plus many minutes of rebreathing my own exhaled air before I feel anywhere near normal. This is one of the reasons I tend to suffer from nightmares at the best of times, even more so when under stress or when anxious or depressed.
There are various things that can be done to minimise dust mite allergy, the worst of my collection that's unavoidable. (Cigarette smoke, salicylates and sulphur dioxide could all claim to be THE worst, but they are all avoidable. Mostly.) If you visit us, you'll notice we have minimal soft furnishings, and most of the ones we do have are washable - and get washed often at 60 degrees C. We have a HEPA filtered vacuum cleaner, but unfortunately it doesn't run itself. We have had this plan to rip out all the carpets and replace them all with wooden floors since before we even moved in, but it's such a major undertaking we haven't got round to it yet. I don't really need any suggestions of other ways for eliminating mites, I do actually know them all.
Anyway. So I've been ignoring various symptoms for a few weeks, on the basis that "I'll be able to rest in a few weeks"; but now I have too many symptoms to ignore. The problem is, the only real way to get my CO2 level back to what it should be is to rest a lot, and almost completely stop talking for a few days-weeks. Not talking is difficult for me at the best of times, let alone when I have a job that involves lots of it! And explaining the facts about the condition to other people is very difficult, even with me being a professional science communicator. Explaining that the work itself is part of the problem is very difficult to explain to students & parents who are stressed-out by imminent exams and wanting to increase the number of hours I spend with their kids, not decrease them :/ The only other option is to make damn certain I rest a hell of a lot at home, and constantly check my breathing, and take time out to breathe properly if I need to, and cut right back on telephone communication. Joy oh joy.
Am also thinking I should actually write a checklist and physically tick it off each week, as a way of keeping track of what's going on. Except that means taking time out to deal with my health problem, which means acknowledging that I have a health problem, which means... yeah, some of you know what I'm talking about.
Anyway. Not looking for advice - really not looking for advice, I've been dealing with this thing for so long that most advice would seem patronising; and if I did happen to need any more I'd go back to the breathing retraining physiotherapists and my textbooks. This is mostly just moaning accompanied by a bit of an explanation for anyone who's ever wondered how anxiety and panic work. Sympathy is welcome, especially from people who also have to deal with broken bodies and/or brains (and the denial about them) on a daily basis. Yay denial!
[*] I live in my conscious brain. There is "me", in my conscious brain, and then there is my hindbrain, which isn't exactly part of "me". It just bimbles along shoving random emotions in at inconvenient times. Thus plural.