When someone goes unconscious from a BJJ blood choke, they are not actually “going to sleep.”
They are fainting.
The medical word for that is syncope. Syncope basically means the brain is not getting enough blood flow for a short period of time, so the body shuts consciousness off for a moment.
In BJJ, when we talk about a “blood choke,” we are usually talking about pressure on the sides of the neck. That pressure affects the carotid arteries, which help bring blood to the brain, and the jugular veins, which help drain blood out of the head.
Now, that does not mean you are cutting off every drop of blood to the brain. The body is more complicated than that. But you ARE restricting blood flow enough that the brain’s blood pressure and oxygen delivery drop quickly.
And the brain is extremely sensitive to blood pressure and sudden drops or spikes.
That is why someone can be completely fine one second, fighting the choke, and then suddenly go limp. It is not because they decided to take a nap. It is because the brain temporarily lost enough blood flow that it could not keep them conscious.
There can also be a reflex involved. Around the carotid artery area, the body has pressure sensors that help regulate blood pressure. If those sensors get stimulated hard enough, the body can respond by dropping heart rate and blood pressure. That can make the person pass out even faster.
Once the choke is released, blood flow quickly returns to the brain, called reperfusion. Most people will wake back up pretty quickly after the pressure is removed.
Sometimes you may see twitching, shaking, eye fluttering, snorting, or weird breathing sounds when someone goes out. That can be scary if you have never seen it before… that is called convulsive syncope.
Convulsive syncope can look like a seizure, but it is not the same thing as an epileptic seizure. It is basically the brain and body reacting to that short drop in blood flow.
If someone goes unconscious from a choke, we release immediately, keep them safe, make sure they are breathing, and do not rush them back up to their feet.
If they do not wake up quickly and if their breathing looks wrong, if they hit their head, stay confused, or if anything seems off, we’ll get medical help.
But this is very uncommon.
The danger is not usually the choke itself when it is applied cleanly and released immediately. The danger is holding it too long after the person is already unconscious. Once someone goes limp, their brain has already lost enough blood flow to shut consciousness off. If the choke stays on, the brain continues to be under-perfused, which can turn a simple temporary faint into a real medical emergency.
A fully established blood choke can make someone unconscious very fast. Loss of consciousness can happen in as little as 2.5–3 seconds, but more commonly averages under 10 seconds once the choke is fully locked in.
That is why we do not “test” chokes, and we do not wait to see what happens. The second someone taps, goes limp, stops defending intelligently, or seems out, we release immediately.
Is Lifting the legs Necessary?
I’ve seen many opinions… mostly uneducated ones… across the BJJ spectrum about this. Ive heard that you must do it, and Ive heard it does absolutely nothing.
In the BJJ Training room, the main thing that makes someone wake up is releasing the choke immediatly and allowing blood flow to return. Lifting the legs is not magic. But it is also not accurate to say it does absolutely nothing.
Standard first-aid guidance says that if someone faints, is breathing, and has no injury, laying them on their back and raising the legs MAY help blood return toward the brain. It doesn’t hurt, and it ‘may’ help.
So the simple version is this:
A blood choke does not “put someone to sleep.”
It temporarily reduces blood flow and blood pressure to the brain until the brain can no longer maintain consciousness. It’s actually more like a ‘Brown out’ than a Black Out.
This is why tapping matters.
Tap early… Release immediately… Train technically… Take care of your partners!
That is how we keep chokes as a controlled part of Jiu-Jitsu instead of turning them into something reckless and dangerous
Train hard, Stay Safe!
Prof. GEO
If you’d like to learn how to perform this technique, and many others, safely and effectively… contact me for a FREE trail Class.
Sources… for the Bro-Science Bitches!!
NCBI Bookshelf / StatPearls — Syncope is described as transient loss of consciousness caused by decreased cerebral blood flow, followed by spontaneous recovery. (NCBI)
Cleveland Clinic — Syncope is fainting caused by a temporary drop in blood flow to the brain. (Cleveland Clinic)
NCBI Bookshelf / StatPearls — Carotid sinus stimulation can trigger reflex changes in heart rate and blood pressure that may lead to syncope. (NCBI)
Cleveland Clinic — Convulsive syncope is fainting that includes jerking movements and can look like a seizure, but it is not the same as epilepsy. (Cleveland Clinic)
Mayo Clinic — First aid for fainting includes laying the person on their back, raising the legs if there are no injuries and the person is breathing, not getting them up too quickly, and calling emergency help if consciousness does not return within about one minute. (Mayo Clinic)
PubMed — Submission-grappling chokes are described as vascular neck compression techniques that reduce cerebral perfusion and can cause loss of consciousness or voluntary submission. (pubmed.ncbi.nlm.nih.gov)
Sportive choke / vascular neck restraint timing and mechanism:
Cerebral hypoxia can cause serious or permanent brain injury:
Neurological injury from limiting brain blood flow can be irreversible: