Why Does Vaginismus Cause a Burning Sensation?

How the Nervous System Interprets Pain in Vaginismus

 

Pain perception, including the burning sensation associated with vaginismus, is a complex process involving the nervous system. Here’s a step-by-step breakdown of how nerve sensitivity contributes to pain:

 

1. PAIN SIGNAL INITIATION (NOCICEPTION)

When the pelvic floor muscles involuntarily contract too tightly, they can compress or irritate nearby nerves. This activates specialized pain receptors called nociceptors, which are responsible for detecting harmful stimuli, such as excessive pressure, stretching, or irritation.

Nociceptors can be triggered by:

• • • • • Mechanical stress (muscle spasms, tension, microtears)
        • Chemical changes (inflammation, increased acidity in tissues)
        • Thermal factors (increased blood flow from irritation)

 

2. TRANSMISSION OF PAIN SIGNALS

Once nociceptors are activated, they send electrical signals through the peripheral nerves to the spinal cord. These signals travel along two primary types of nerve fibers:

• • • • A-delta fibers – Fast-conducting nerves that transmit sharp, localized pain.
      • C fibers – Slower-conducting nerves responsible for dull, burning, or aching pain.

Since vaginismus is often associated with prolonged muscle tension, the C fibers are more likely to be involved, explaining the burning or aching sensation.

 

3. PROCESSING IN THE SPINAL CORD (CENTRAL SENSITIZATION)

When pain signals reach the spinal cord, they pass through the dorsal horn, which acts like a relay station. Sometimes, if the pain is persistent, the spinal cord itself becomes sensitized, amplifying pain signals even more. This can make normal touch or pressure feel painful, a phenomenon called allodynia.

 

4. PAIN PERCEPTION IN THE BRAIN

From the spinal cord, signals travel to different areas of the brain:

• • • • The thalamus – Sorts and directs pain signals.
      • The somatosensory cortex – Determines where the pain is coming from and its intensity.
      • The limbic system – Processes the emotional impact of pain (anxiety, fear, or distress).

This explains why pain from vaginismus can feel overwhelming—it’s not just physical; the brain also processes the emotional component, potentially increasing pain perception.

 

5. PAIN RESPONSE & MODULATION

Once the brain registers the pain, it can either:

• • • • Amplify it (if stress and fear are present, leading to more muscle tightness and pain).
      • Reduce it (if the brain releases natural painkillers like endorphins and serotonin).

Unfortunately, anxiety can keep the pelvic floor muscles in a constant state of contraction, leading to a cycle where pain triggers more tightness and sensitivity.