The needle goes in. You feel a dull ache, heaviness or spreading warmth. Then a deep sense of relaxation washes over you. What is actually happening in your body at that moment? The answer involves your nervous system, your connective tissue, your brain chemistry — and something classical medicine called Qi arriving at the point.
What Happens to Your Body During Acupuncture
The Neuroscience and Classical Mechanics of Acupuncture
When an acupuncture needle is inserted to the correct depth and angle, it mechanically engages the connective tissue (fascia). Research by Helene Langevin shows the tissue winds around the needle like a spindle during rotation, creating a sustained mechanical signal that travels through the fascial network to distant tissues.
This signal travels via A-delta and C-nerve fibres to the dorsal horn of the spinal cord, where it inhibits pain signals (the “gate control” mechanism). Simultaneously, the needle activates the brain’s hypothalamus-pituitary axis, releasing endorphins, enkephalins and serotonin—producing the characteristic post-acupuncture calm.
Functional MRI studies show acupuncture deactivates the limbic system (the brain’s alarm centre) and activates the default mode network (rest and recovery mode). The classical concept of Deqi—the sensation of Qi arriving at the needle—corresponds to this connective tissue engagement. Practitioners look for this as confirmation that the point has been activated correctly.
The “relaxed but alert” state many patients experience during and after acupuncture is a well-documented parasympathetic nervous system response. This is why acupuncture has effects well beyond the local needled area—it is a systemic neurological event, not just a local tissue intervention.
Key Concepts
What Does the Research Show?
Frequently Asked Questions
What is the Deqi sensation?
Deqi means Qi (vital energy) has arrived at the needle location. Classically, it feels like heaviness, soreness, aching, or tingling around the needle. Modern research shows it correlates with fascial engagement. It indicates the point has been activated correctly.
Why do I feel so relaxed after acupuncture?
Acupuncture deactivates your brain’s alarm system (amygdala and limbic system) and activates the parasympathetic nervous system (rest and recovery). Endorphins and serotonin are released. This relaxation is a measurable neurological response, not just placebo.
Does it matter if I don’t feel anything during needling?
Not necessarily. While Deqi indicates successful activation, some people are less sensitive to the sensation. The neurological effects (endorphin release, parasympathetic activation) happen regardless of how much sensation you feel.
Why does needling one area affect a completely different area?
The connective tissue (fascia) is continuous throughout the body. Research by Helene Langevin shows the tissue winds around the needle, creating mechanical signalling that travels through this fascial network. This explains propagated sensations and distant treatment effects.
Is the relaxation effect consistent?
Yes, for most people. However, stress levels, caffeine intake, sleep deprivation, and anxiety can temporarily reduce the effect. Regular treatment typically produces more consistent and stronger responses as the body learns to relax more deeply.