Hypermobility causes fatigue through several overlapping mechanisms, not just one. Loose joints force your muscles to work harder for basic stability, your cardiovascular system struggles to regulate blood flow, chronic pain rewires your nervous system, and sleep quality suffers. These aren’t separate problems that happen to coexist. They feed into each other, creating a cycle where fatigue becomes one of the most persistent and disabling symptoms of hypermobility spectrum disorders (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS).
Your Muscles Work Harder for Basic Movement
When connective tissue is too stretchy, your ligaments can’t do their usual job of holding joints in place. Your muscles have to pick up the slack, firing constantly to stabilize joints that would otherwise move beyond a safe range. This isn’t a conscious effort. Your body does it automatically, and the energy cost adds up fast.
Research published in Frontiers in Rehabilitation Sciences found that people with HSD and hEDS have a significantly higher metabolic cost of walking compared to people without hypermobility, at every speed tested. The extra energy doesn’t come from where you might expect. Rather than the ankles doing more work, studies show the body redistributes effort to larger joints like the hips and knees. Muscles around these joints activate more intensely, and opposing muscle groups fire simultaneously (a pattern called coactivation) to brace unstable joints during movement. This compensatory bracing happens with every step, every reach, every time you stand up from a chair. By mid-afternoon, you’ve spent energy that someone with typical connective tissue never had to budget for.
Blood Flow Regulation Falls Short
Roughly two-thirds of people with hEDS experience orthostatic intolerance, meaning their body struggles to maintain stable blood pressure and heart rate when they change position. About 41 to 50% of those individuals meet the criteria for postural orthostatic tachycardia syndrome (POTS), a condition where the heart rate spikes excessively upon standing.
The connection to fatigue is direct. In a study published in Rheumatology, researchers used tilt-table testing to compare cardiovascular responses in people with hEDS versus controls. The hypermobile group responded with a higher heart rate and lower resistance in their blood vessels, meaning blood pooled in their lower body instead of circulating efficiently to the brain and muscles. This altered cardiovascular response correlated with everyday fatigue levels. The hypermobile group also reported a dramatically larger spike in fatigue from the tilt itself: an average increase of 3.1 points on a rating scale, compared to just 0.5 in controls.
In practical terms, this means activities that involve standing, walking through a grocery store, or even sitting upright for long periods can drain your energy in ways that feel disproportionate to the effort involved. Your heart is working overtime to compensate for blood vessels that are too compliant, and that cardiovascular strain translates directly into exhaustion.
Chronic Pain Rewires Your Nervous System
Pain is exhausting on its own, but hypermobility-related pain does something more insidious. When joints subluxate, overextend, or ache day after day, the nervous system begins to amplify pain signals. This process, called central sensitization, means neurons in pain pathways become increasingly excitable. Inputs that wouldn’t normally register as painful start triggering pain responses, and the volume on existing pain gets turned up.
Central sensitization doesn’t just amplify pain. It comes packaged with fatigue, sleep disruption, memory difficulties, and mood changes. The same overactive nervous system that magnifies pain also disrupts sleep architecture, drives the sympathetic (“fight or flight”) nervous system into overdrive, and creates what’s sometimes described as global sensory amplification, where sounds, lights, and textures also become more draining. Chronic fatigue syndrome is explicitly listed among the conditions associated with central sensitization, and the overlap with hypermobility is substantial.
This creates a feedback loop: pain causes fatigue, fatigue lowers your pain threshold, and lower pain tolerance increases the nervous system’s tendency to amplify signals further.
Sleep Problems Hide in Plain Sight
Many people with hypermobility wake up unrefreshed no matter how many hours they spend in bed. Part of the explanation is structural. Connective tissue laxity affects the soft tissues of the airway, and research has found that sleep-disordered breathing is remarkably common in Ehlers-Danlos syndrome. In one study, every patient with EDS who underwent a formal sleep study showed some form of abnormal breathing during sleep, including apneas (pauses in breathing), shallow breathing, and airflow limitation.
These breathing disruptions pull you out of deep, restorative sleep stages repeatedly throughout the night without necessarily waking you fully. You may have no idea it’s happening. The result is that sleep fails to do its repair work, and you start each day already in an energy deficit. Abnormalities in jaw and facial structure related to connective tissue differences may contribute to airway narrowing, making EDS a potential genetic model for obstructive sleep apnea.
Gut Problems Cut Off Your Fuel Supply
The connective tissue that’s too stretchy in your joints is the same type of tissue found throughout your digestive tract. Gastrointestinal symptoms are extremely common in hEDS, including slow stomach emptying (gastroparesis), irritable bowel syndrome, chronic constipation, and small intestinal bacterial overgrowth (SIBO). These conditions interfere with your body’s ability to absorb nutrients efficiently.
On top of malabsorption, many people with hEDS develop food intolerances that lead to increasingly restricted diets. The combination of poor nutrient absorption and limited food variety raises the risk of deficiencies in vitamins and minerals that are essential for energy production. When your cells can’t get adequate fuel, fatigue follows regardless of how much rest you get.
Neuroinflammation and Brain Fog
There’s growing evidence that low-grade inflammation in the brain contributes to the cognitive fog and deep fatigue many people with hypermobility describe. Chronic pain and fatigue appear to activate inflammatory pathways that affect the brain, with pro-inflammatory signaling molecules potentially crossing a blood-brain barrier that may be more permeable than normal in people with connective tissue disorders.
This neuroinflammation can disrupt the neural circuits responsible for cognition, emotional regulation, and energy. Some people with hEDS also have conditions like Chiari malformation or craniocervical instability, where the upper spine and skull base are insufficiently supported. These structural issues can alter cerebrospinal fluid pressure, further contributing to cognitive fog, disrupted sleep, and fatigue. The result is a type of exhaustion that feels mental as much as physical, where thinking clearly requires effort that compounds the overall energy drain.
Why These Factors Compound Each Other
What makes hypermobility-related fatigue so difficult to manage is that none of these mechanisms operate in isolation. Poor sleep worsens pain sensitivity. Amplified pain increases muscle guarding around joints, raising the metabolic cost of movement. Dysautonomia disrupts gut motility, worsening nutrient absorption. Nutritional deficits reduce exercise tolerance, leading to deconditioning, which worsens orthostatic intolerance. Each factor feeds the others.
Fatigue is now recognized as a core feature of EDS and hypermobility spectrum disorders in the 2017 international diagnostic framework, not a secondary complaint. The consortium that developed these criteria specifically noted that pain, fatigue, cognitive dysfunction, and dysautonomia are “often underappreciated” in these conditions, particularly because symptoms wax and wane. On good days, the fatigue may lift enough to feel almost normal. On bad days, the accumulated load from all these systems failing to compensate can make even basic tasks feel impossible. Understanding that this fatigue has multiple concrete, physiological drivers, not a single cause, is the first step toward addressing it effectively.