Let us assume a very common choking technique (for example hadaka jime) performed on an average adult. If I understand correctly what I could gather from other questions, the main mechanism involved is compression of the carotid arteries. What I couldn’t find at all in answers to other questions is: what happens to the person? During how many seconds would you say he can realistically fight back, as opposed to only witnessing himself losing consciousness? Does his face become blue (cyanosis), or another colour? Does he sweat? Does he shake ? Does he make uncontrolled movements? Does he lose control over body functions ? Does anything else happen? Do several things happen in succession; if so, in which order?
Philip Klöcking has done a good job covering what the person being choked experiences. I will try to cover other considerations.
In my experience, feeling pain is largely separated from whether a choke successfully cuts off blood flow. Pain will usually cause people to tap even when the blood choke is not that effective. You can also choke such that the choke is not painful and does not impair breathing but is very effective in cutting off blood.
Resistance time varies widely. This depends on the person doing the choking, the person being choked, and more.
If a choke is not tight and continuous, it's often possible to resist for > 30 seconds. Any time the person being choked can temporarily relieve pressure increases resistance time. In competitive judo, the match will be stopped and the referee will stand the competitors back up fairly quickly. For poor referees, this can be before the choke has sufficient time to work.
When a choke is done very skillfully, you may not even have a chance to recognize the danger and tap before you pass out. This can be true both of rolling chokes where the pressure increases suddenly, and of the painless variety of choke.
I think time to pass out also depends on the physical state of the person being choked. I would hypothesize that competitors in match conditions with high heart and breathing rates pass out faster than people at rest.
While someone is being choked effectively, I usually see the following, in order:
- blood vessels in the head begin to bulge
- face color begins to darken
- eyes become glassy
After someone passes out, they may shake, sputter, urinate, or simply go limp. In the dozen or so cases I have seen, I would not say there is a normal set of things that happen or order that they occur in. This makes it difficult to tell when someone has passed out. When practicing chokes, I highly recommend having a third party present because they can often recognize someone has passed out before the choker.
Subjective experience report incoming:
It very much depends on the quality of the application and the strength ratios. The better the technique is applied and the stronger my opponent in relation to my choke resistance training is, the faster it will end. I can have students choking me at full strength without fading out just by resisting through neck muscles. But with an opponent of comparable strength and/or perfect technique, I will have to use my hands, elbows and whatever it takes.
Your face becomes red.
Normally, there is a sort of paralysis, the body concentrates on taking countermeasures against the actual choke and it takes some will-strength to move apart from that, e.g. to stand up.
You have 3-8 seconds to fight back before fading as soon as the application is effective.
Your field of vision blacks out "from the outside in", i.e. the field of your vision becomes smaller until there is only a small circle in the middle of what you normally see surrounded by blackness moments before you become unconscious (think of the iris of a camera or like in Stargate, closing slowly). If the choke ends then, this black "iris" opens again from the inside out. Exactly the same effect as a "black-out" experience by combat pilots at high g pressures "downwards", i.e. into the seat.
The world goes slow motion. Seriously. It feels like much more time.
If you have no effective counter within the first seconds, your strength begins to fade gradually. But you can perfectly act at will all the time as long as you do not panic.
After some seconds, movements are becoming more rare, slower, less effective from an outside view. But they are definitely controllable from an inside perspective all the time. Tapping out would be quite pointless otherwise.
After-effects are disorientation, lack of balance, and weakness. That is why being choked is dangerous even if you do not get unconscious. It is the same as bathing too hot and then standing up rapidly: Your body has to regulate your blood circulation and pressure, which is highly out of balance.
I took the question "What happens to a person being choked" a bit more physiologically. From what I understand (from a 'straight dope' posting almost 20 years ago), a properly applied "blood choke" (as opposed to an "air choke), fools the body's defense mechanism into thinking that the brain is suddenly receiving a spike in blood pressure - which can be damaging. Along the arteries in the sides of the neck, there are these sensors called baroreceptors which sense pressure via deformation/bulging of the arteries. Normally, these provide feedback to modulate the heartrate in small steps, but if the baroreceptor suddenly detects an apparent spike in blood pressure, it signals the heart to quickly 'slow down', while trying to regulate the amount of blood in the head by diverting blood to other areas. This sudden lack of blood to the brain usually causes you to 'lie down' by passing out. Supposedly, based on personal experience leading up to (but not past the point) of passing out, the literature, videos, interviews, talks, lectures, etc., a properly applied blood choke will lead to unconciousness in 5 seconds or less.