Subspace is actually a mashup of two shortened words:
sub – short for submissive, which can be generally defined as “person who consensually gives up control either all the time or for a specified period”
space – short for headspace, slang for mental state

The Merriam-Webster Dictionary might offer a better definition of submissive as “characterised by tendencies to yield to the will or authority of others”. Generally, we draw a mental line between sub and bottom. Although a bottom might give up physical control, they don’t necessarily “submit” to a Dominant.

When the body is subject to stresses, like pain, it produces adrenaline, which is the fight or flight response, and then endorphins (which is a mashup of two other words: endogenous morphine). The job of the endorphins is to counter the pain and it does this through a mental response, not by actually numbing the body in the way that an anesthetic from your doctor would. It alters the way the brain processes and responds to the pain.

So, the person on the receiving end of an S&M scene is effectively getting shots of a type of morphine, which leads to an “endorphin high”. That high, which often gets called “bottomspace” or “flying” is the body’s way of dealing with pain.

Is it the same as subspace?

It’s the same chemical process, but the result is different. Subspace, by definition, involves feelings of subservience, or colloquially “subbiness”. The endorphins still flood the brain, but the brain processes the feelings in a different way.

Although the term “subspace” gets thrown around liberally to define endorphin highs, it’s not actually always the correct term. Yes, neurochemicals like adrenaline, endorphins, dopamine, prolactin, cortisol and oxytocin do play an important part, but subspace is a particular way that the feelings are processed.

It’s a small distinction, but if you want to understand subspace it’s an important one.

FURTHER READING

• Sexis Social – BDSM Roller Coster: Subspace to Sub-drop
• FetLife – Subspace and Endorphins
• FetLife – Subspace – What it is, how to get there, how it feels
• Frisky Business Boutique – The Endorphin Levels in BDSM
• The Telegraph – Love Hormone Oxytocin Helps Soldiers Like Each Other and Hate The Enemy
• Submissive Guide – Exploring Hormone Junkies: Part 2 – Oxytocin
• Rose Colored Asses –The Science Behind BDSM
• Sir Joe – What Exactly Is Subspace and… What Is It Not?