This is a topic no one seems to want to talk about but it's a real concern in BDSM play.  Out of the thousands of hours of sessions I've been involved in I have had this happen maybe 15 times - so although it's rare, it does happen.

BDSM play can be strenuous and intense but it isn't always extreme situations that cause a submissive to faint or pass out.  When you lose consciousness it's because the body is under stress and decides to shut down.  The combination of adrenaline and odd positioning that often accompany a session can be enough in itself to cause an event.  Throw in a little pain and the ante goes up.  The following are just some of the causes of fainting in session:

*Lack of hydration
*Hypoglycemia (low blood sugar) - including Non-Diabetic Hypoglycemia
*A sudden lowering of blood pressure (many causes including ED drugs, vasovagal stimulation from pain, etc.)
*Extreme temperatures
*Lack of blood flow
*Underlying heart issues or circulatory issues

There are a plethora of factors that can contribute to fainting in session and it can happen to anyone, at any age, so heed the following precautions:

1. Hydrate well prior to a session.  In My experience lack of hydration is the #1 factor.   For longer sessions, bring water or a sports drink.

2. Avoid erectile dysfunction drugs like Cialis and Viagra.  I know it's fun to have a raging hard-on in session but ED drugs lower blood pressure (see above) and if you are on alpha blockers or nitrate drugs this can make the effect worse and is dangerous.  If you do take ED drugs for a session, move slowly when changing positions, avoid positions of standing immobility and by all means inform your Domme.

3. Eat normally prior to a session.  I know some subs can get a "case of the nerves" prior to sessioning and have a loss of appetite, but coming to a session on an empty stomach could have you ending up on the floor. Eat and drink normally at least 30 minutes prior to your session.

4. When placed in standing positions. like on the St. Andrews cross, don't lock your knees.  It lowers circulation to the brain.

5. If you get overheated easily and you are going to be engaging in very physical play or even cross-dressing, ask that the room temperature is lowered.  An overly warm room can cause light-headedness and subsequent fainting in some subs.

6. Be honest in your dealings with your BDSM provider.  If you have ever felt lightheaded, dizzy or lost consciousness in session, tell them up front.  Some subs are just more prone to this.  That way she can take the necessary precautions.  Be honest about medical conditions, your age, medications and other relevant information she requires.  If she chooses not to see you because of it, so be it.  It could be a disaster if she is unprepared to deal with your condition.

7. At the first sign of lightheadedness, dizziness or disorientation - tell your Top immediately so they can take the necessary measures to keep you safe.

Advice for Tops:

In my personal experience, ED drugs, CBT and the St. Andrews cross = a perfect storm.  One of the factors is lack of circulation due to locked knees and hands above the heart in this position.  Use extreme caution in this situation or avoid it all together if you are not familiar with the sub and his responses.  The good news is, most subs revive quickly once you lay them flat.  They may be disoriented for a few seconds and think they were out longer than they were, but it's usually only for a few seconds.

If your sub loses consciousness, the most important thing is not to panic.  The biggest issue you have at this point is moving them safely to a prone position.  If they are on the cross, unhook the legs first and pull them out a bit so they don't fall forward when you release their hands.  Have full weight release clamps on the wrist connectors.  Their full weight will be on their wrists and it will be difficult (if not impossible) to unclamp them without release clamps.  While releasing the wrists, push your shoulder into their torso to bear their weight the best you can and guide them to the floor.  The bigger the sub the harder they will fall and this can be a difficult maneuver to do on your own, but they must come down in order to wake up.

Once they are flat on the floor aid in circulation by propping their feet up above their heart.  As stated, most subs wake instantly, but it's still a good idea to have them rest in this position for a while before trying to move.  Give them water to sip.  Simple sugars like juice or hard candy (always keep some candy in your play bag) are helpful in cases of insulin drop.   Most subs are able to rest for 5-10 minutes and want to continue the session but use your discretion as to whether to continue or not and if you do, keep them in sitting or lying positions.  Tables are best but I have never had an issue on a spanking bench either.

If your sub does not revive quickly or becomes incontinent this is not a good sign and it's time to call emergency response.

Although I did have this post reviewed by a doctor/sub client, it is not meant to be all encompassing and if in doubt, always err on the side of caution.  
_________________________
Making grown men cry . . . and loving every minute of it.

Main website: www.mistressayn.com
Content site: www.aynrules.com
Follow Me on Twitter - @MistressAyn