Fibromyalgia and Cortisol: Understanding the Stress Response

Fibromyalgia is a chronic condition characterized by widespread pain, fatigue, unrefreshing sleep, and cognitive difficulties. Researchers have investigated whether alterations in cortisol and the body's stress-response system may contribute to these symptoms.

Although the relationship is complex, studies suggest that dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis may play a role in fibromyalgia in some individuals.

What Is Cortisol?

Cortisol is a hormone produced by the adrenal glands that helps regulate the body's response to stress, metabolism, immune activity, and sleep-wake rhythms.

The HPA axis coordinates cortisol release in response to physical and psychological demands. Normally, cortisol follows a daily rhythm, typically rising around awakening and declining throughout the day.

Chronic pain, disrupted sleep, and prolonged stress may interact with this system. Researchers are investigating whether altered HPA-axis regulation contributes to the symptoms experienced by people with fibromyalgia.

What Does the Research Show?

1. Lower Cortisol Levels

A 2010 study involving 29 women with fibromyalgia and 29 healthy controls found lower salivary cortisol levels in the fibromyalgia group, particularly in the morning after awakening.

The findings suggested that altered HPA-axis activity might contribute to the condition, although a small study cannot establish causation.

2. A Systematic Review of Cortisol and Pain

A 2020 systematic review and meta-analysis examined studies investigating cortisol and pain in fibromyalgia. The authors found inconsistent results and concluded that further research was needed to clarify the relationship between cortisol levels, pain sensitivity, and treatment outcomes.

3. A Larger Meta-Analysis of Stress Biomarkers

A 2023 systematic review and meta-analysis included 47 studies involving 1,465 people with fibromyalgia and 1,192 controls. The researchers found lower salivary and urinary cortisol levels on average, but no consistent differences in blood cortisol. They also identified substantial variability among studies, suggesting that cortisol patterns differ depending on the population and measurement method.

4. Hair Cortisol and Symptom Severity

A 2023 study investigating hair cortisol found that levels varied with both the duration and severity of fibromyalgia. Greater symptom severity was associated with higher hair cortisol, while longer disease duration was associated with lower levels.

These findings suggest that the relationship between chronic pain and cortisol may change over time rather than follow a single pattern.

Does Fibromyalgia Mean Cortisol Is Too Low?

Not necessarily. Although some studies report lower cortisol, others find normal or elevated levels. Cortisol is influenced by sleep, medications, stress, sampling time, and other factors.

It is therefore inaccurate to assume that everyone with fibromyalgia has low cortisol or “adrenal fatigue.” Adrenal insufficiency is a distinct medical condition that requires appropriate clinical evaluation.

Routine cortisol testing is not established as a diagnostic test for fibromyalgia. When symptoms suggest an endocrine disorder, testing should be selected and interpreted by a qualified clinician.

Supporting Stress Regulation and Sleep

Because sleep disruption and stress can worsen pain and fatigue, a comprehensive fibromyalgia care plan may include:

• Sleep support: Addressing insomnia, sleep apnea, and irregular sleep schedules.
• Stress management: Using individualized relaxation techniques, mindfulness, or psychological support.
• Pacing and physical activity: Gradually building activity while avoiding repeated cycles of overexertion and symptom flares.
• Medical evaluation: Investigating other potential contributors to fatigue, including thyroid disorders, anemia, and genuine adrenal dysfunction when clinically indicated.

These strategies can support overall well-being without assuming that correcting cortisol levels is the primary treatment for fibromyalgia.

The Bottom Line

Research suggests that altered HPA-axis regulation may be associated with fibromyalgia, but cortisol findings are inconsistent. Some studies report lower cortisol, others find elevated levels, and many show no clear difference.

The evidence supports further investigation into how stress physiology interacts with chronic pain, sleep, and fatigue. However, cortisol testing or hormone treatment should not be used routinely to treat fibromyalgia without a specific clinical indication.

At Valley Integrative Health , we believe in evaluating the multiple factors that may contribute to persistent symptoms while grounding treatment decisions in current scientific evidence.

This article is for educational purposes only and is not a substitute for individualized medical advice.

References

1. Riva R, et al. Fibromyalgia syndrome is associated with hypocortisolism. 2010.
2. Úbeda-D'Ocasar E, et al. Pain and Cortisol in Patients with Fibromyalgia: Systematic Review and Meta-Analysis. Diagnostics. 2020;10(11):922.
3. Beiner E, et al. Stress biomarkers in individuals with fibromyalgia syndrome: a systematic review with meta-analysis. Pain. 2023.
4. A two-component model of hair cortisol concentration in fibromyalgia: Independent effects of pain chronicity and severity. European Journal of Pain. 2023.