What Happens with Fibromyalgia?

What is actually happening inside my body?

Fibromyalgia can be confusing because the symptoms are very real: widespread pain, fatigue, sleep problems, brain fog, and so much more, yet standard medical tests often appear normal.

Over the past two decades, research has dramatically improved our understanding of fibromyalgia. Scientists now recognize that fibromyalgia is primarily a condition involving how the brain and nervous system process pain and sensory signals.

Rather than a problem with muscles or joints themselves, fibromyalgia appears to involve changes in pain regulation, nervous system sensitivity, sleep regulation, and stress responses throughout the body.

Understanding these changes can help make sense of many of the symptoms experienced. Let’s take a closer look.

1. Amplified Pain Processing

One of the key features of fibromyalgia is that the brain processes pain signals differently.

Researchers describe this as central sensitization, meaning the nervous system becomes more sensitive to incoming signals from the body.¹

In practical terms, this means:

• sensations that normally would not hurt may become painful
• painful sensations may feel stronger than expected
• pain may spread beyond the original source
• the nervous system becomes more reactive overall

The brain essentially turns up the volume dial on pain signals.

Because this change occurs in the nervous system rather than in injured tissue, traditional imaging tests often do not show a clear cause for the pain.

This does not mean the pain is imagined. It means the body's alarm system has become overly sensitive.

2. Nociplastic Pain

Fibromyalgia is now classified by many experts as a form of nociplastic pain.

Nociplastic pain occurs when pain arises from altered pain processing in the nervous system, rather than from clear tissue damage or inflammation.²

This category helps explain why fibromyalgia symptoms can include:

• widespread body pain
• tenderness to touch
• deep muscle aching
• heightened sensitivity to pressure, temperature, or sound

The pain is real, but its source lies primarily in how the nervous system interprets signals, not necessarily in damaged tissues.

3. Disrupted Sleep

Sleep disturbances are one of the most common symptoms of fibromyalgia.

Many people report feeling as though they never wake up fully rested, even after a full night in bed.

Research suggests that people with fibromyalgia often have disruptions in deep restorative sleep, which is the stage of sleep when the body repairs tissues and regulates many biological systems.³

When deep sleep is disrupted, the body may struggle to regulate:

• pain sensitivity
• immune function
• energy levels
• mood and cognition

Poor sleep can therefore intensify many of the symptoms associated with fibromyalgia.

4. Brain Fog and Cognitive Changes

Another common symptom of fibromyalgia is cognitive difficulty, often called fibro fog.

People may experience:

• difficulty concentrating
• memory lapses
• slowed thinking
• trouble finding words

These symptoms are believed to be connected to changes in how the brain processes information when the nervous system is under persistent stress.

Pain, fatigue, and sleep disruption can all affect cognitive function, making mental clarity more difficult.

5. Autonomic Nervous System Dysregulation

The autonomic nervous system controls many automatic body functions, including heart rate, digestion, temperature regulation, and stress responses.

Some research suggests that people with fibromyalgia may experience autonomic nervous system dysregulation, meaning these systems may not regulate themselves as smoothly as they should.⁴

This may contribute to symptoms such as:

• feeling wired but exhausted
• dizziness when standing
• temperature sensitivity
• digestive issues
• heart palpitations
• difficulty relaxing

These symptoms reflect how closely the nervous system is connected to many systems throughout the body.

6. Sensory Sensitivity

Many people with fibromyalgia notice increased sensitivity to sensory input.

This can include sensitivity to:

• light
• noise
• temperature
• touch
• certain smells
• crowded environments

These sensitivities occur because the nervous system becomes more reactive to incoming signals.

When the brain's sensory filtering system becomes overwhelmed, even normal stimuli can feel intense or draining.

7. The Whole-Body Effect

Fibromyalgia affects multiple systems at once because the nervous system connects the entire body.

When the brain’s pain and stress regulation systems become dysregulated, the effects can appear in many areas of health.

This is why fibromyalgia symptoms may include:

• widespread pain
• fatigue
• sleep disruption
• cognitive changes
• digestive problems
• headaches
• mood changes
• sensory sensitivity

Rather than a collection of unrelated symptoms, fibromyalgia represents a pattern of nervous system dysregulation affecting many body systems simultaneously.

What This Means for Healing

Understanding what happens in the body with fibromyalgia can change the way people approach healing.

Instead of focusing only on pain itself, many effective strategies aim to support the systems involved in pain regulation.

These approaches often include:

• nervous system regulation
• restorative sleep practices
• gentle movement
• anti-inflammatory nutrition
• pacing and energy management
• stress recovery practices

While fibromyalgia can feel overwhelming, the nervous system is also capable of change.

Research on neuroplasticity shows that the brain and nervous system can adapt and form new patterns over time.

With the right support, many people find that symptoms can gradually improve.

A Note From Lived Experience

Living with fibromyalgia for more than 25 years has taught me something important.

When symptoms first appear, it often feels as though the body has suddenly turned against us.

But as I learned more about the nervous system and the science of chronic pain, I began to see fibromyalgia differently.

My body was not failing.

It was reacting and trying to protect me in ways that had become overactive.

Understanding what is happening inside the body can be incredibly empowering because it opens the door to new ways of supportive healing.

Fibromyalgia may be complex, but the body is also capable of remarkable adaptation.

Sources

1. Clauw DJ. Fibromyalgia: A clinical review. JAMA.

2. International Association for the Study of Pain. Nociplastic pain definition.

3. Moldofsky H. Sleep disturbances in fibromyalgia. Rheumatic Disease Clinics.

4. Häuser W et al. Fibromyalgia pathophysiology. Nature Reviews Rheumatology.