Muscle Cramps and Night Cramps

Muscle cramps and night cramps are commonly reported by individuals with hypermobile Ehlers-Danlos syndrome (hEDS)—often as part of a broader constellation of neuromuscular symptoms such as myalgia, muscle weakness, and fatigue. Though not included in the formal diagnostic criteria, they are a frequent and sometimes disabling symptom, particularly when they disrupt sleep or limit physical function.

Prevalence

• Studies have documented a higher prevalence of cramps in hEDS patients compared to the general population.

• These symptoms frequently appear alongside muscle fatigue, myofascial pain, and weakness, and can significantly impact activities such as handwriting, opening jars, walking, and sleeping.

Symptoms

• Sudden, painful, involuntary muscle contractions, especially in the calves, feet, and thighs

• Often occur at night (nocturnal cramps) or after exertion

• May involve visible muscle hardening or spasms

• Can cause lingering soreness or fear of movement

• Often disrupt sleep and contribute to cumulative fatigue and pain flares

Causes and Mechanisms

Empirically Observed Causes

• Mild myopathic changes: Muscle biopsy, EMG, and ultrasound in some hEDS cases show neurogenic and myopathic features

• Muscle-ECM dysfunction: Abnormal interaction between muscle fibers and extracellular matrix due to collagen defects

• Peripheral nerve involvement: May contribute to abnormal firing or muscle irritability

• Joint instability and connective tissue fragility: Cause compensatory muscle overuse and fatigue, which can lead to cramping

• Deconditioning and muscle fatigue: Weak or overused muscles are more prone to spasm

• Electrolyte imbalances: Especially in the context of dysautonomia or GI dysfunction

Theoretical Mechanisms

• Abnormal fascial remodeling: Changes in fascia may limit smooth muscle gliding or contribute to chronic tension

• Altered proprioceptive feedback: May lead to poor motor coordination and excessive tension in stabilizing muscles

• Autonomic dysregulation: Poor vascular tone may reduce oxygenation to muscles during rest, especially at night

Management and Treatment

Empirically Used Treatments

• Physical therapy

  • Gentle stretching to reduce spasm

  • Strengthening to reduce compensatory strain

  • Proprioceptive training to improve motor control

• Occupational therapy

  • Adaptive strategies for handwriting, grip tasks, and fine motor strain

  • Energy conservation techniques

• Magnesium supplementation: Often used empirically; some patients report benefit despite limited formal evidence

• Bracing and orthotics: Support joint alignment, reduce overuse, and help minimize cramp-inducing instability

• Hydration and electrolyte support: Especially important in those with dysautonomia

• Massage and heat therapy: For muscle relaxation

• Sleep support: Addressing sleep disorders can indirectly reduce night cramping

Theoretical or Adjunct Approaches

• Addressing fascial dysfunction (e.g., myofascial release)

• Neuromodulation techniques (e.g., TENS units)

• Central nervous system regulation (e.g., improving vagal tone through breathwork or mindfulness)

• Investigation of comorbidities such as small fiber neuropathy or mitochondrial dysfunction in refractory cases

Summary

Muscle cramps—especially night cramps—are a common, multifactorial complication of hEDS. They are linked to connective tissue fragility, altered muscle recruitment, and possible neurogenic or myopathic changes. These symptoms can impair daily function, sleep, and quality of life, especially when compounded by other hEDS features like fatigue and proprioceptive dysfunction.

Management is supportive and multidisciplinary, combining physical therapy, lifestyle modification, and symptom-based care. Though more research is needed, targeting instability, overuse, and sleep quality appears to offer the best symptom control.