Method Am I blacking out?

[M.i.245541]

I have been trying to find the right way to pressure my carotid artery to black out, to prepare myself for full or partial suspension.

I believe that I have found the spots around my neck and I'm able to press them with my 2 hands. This doesn't impact my breathing which is correct from what I read.

At first, I have a very nice feeling like I'm falling asleep. But after few seconds, I feel like I'm compressed and I start feeling very bad, like having a clostrophobia attack. Sometimes, my head start to throb sharply . All these happen within 20 seconds or so. I usually stop there because it's really painful and uncomfortable.
Once I pushed through and I felt that I almost lost consciousness, maybe I did for a couple of seconds. But then my hands were shaking uncontrollably for a minute.

Am I getting near to blacking out? Am I doing it correctly? What is that horrible feeling of being squeezed, compressed?

 

[M.i.245541]

Bump

 

[evanescent_eva]

Tl;dr: At least that one time, you did it mostly right, but applying more force to your neck might reduce your headaches and make you black out quicker.

Longer explanation: The jugular veins and the carotid arteries are basically right next to each other within your neck, so f you're going to apply pressure to the carotid arteries, you're more than likely going to apply pressure to your jugular veins, too. The jugular veins carry blood from your brain to your heart, while the carotid arteries carry blood from your heart to your brain. As a result, when you compress the jugular veins, your brain starts to swell because blood isn't able to leave your brain - this is likely what is causing the sharp throbbing feeling in your head. By contrast, when you compress the carotid arteries, blood isn't able to enter your brain fast enough to keep your brain fully oxygenated, which causes symptoms of hypoxia - which in turn can include feeling like you're falling asleep, dizziness + lightheadedness + reduced sense perception + tunnel vision (likely the cause of your claustrophobia), and decreased cortical regulation of your motor neurons (which is why your hands started shaking).

Importantly, it only takes ~2kg of force to fully compress the jugular veins, while it takes ~5kg of force to fully compress the carotid arteries. If you apply more than 5kg of force to your carotid arteries, you will typically black out within 5-15 seconds. If you apply less than 5kg of force, but more than 2kg, you will partially occlude your carotid arteries while fully occluding your jugular veins. This will result in blood continuing to flow into your brain (at a reduced rate) without being able to leave, causing headaches and a slower onset of hypoxia, if it even happens at all.

Moral of the story: more pressure = fewer headaches + blacking out faster (unless you apply the pressure too low on your neck, in which case you'll only compress the jugular veins, which will suck for youuuu)