Different Causes of Hypermobility

Understanding Different Causes of Hypermobility

Hypermobility is a clinical sign, not a single diagnosis.

It describes joints that move beyond the range typically expected, but this can occur for different reasons.

For some people, it’s a natural variation in how their body moves.

For others, it reflects differences in connective tissue, development, or how the body functions over time.

You might recognise yourself in more than one of these — or not feel like you fit neatly into any category at all.

These categories are not fixed or separate — many people sit across more than one.

Why This Matters

Understanding why hypermobility is present can help make sense of the bigger picture.

In clinical practice, this is particularly important because different causes of hypermobility can present in similar ways, but require different considerations.

For example, hypermobile Ehlers-Danlos syndrome (hEDS) is diagnosed by excluding other conditions that may present similarly.

For many people, this process takes time — and it’s okay if things don’t feel fully clear yet.

Connective Tissue Conditions

Some forms of hypermobility are linked to differences in the structure of connective tissue, the material that provides support and stability throughout the body.

This includes:

Ehlers-Danlos syndromes (EDS)

  • More common:

    • Hypermobile (hEDS) → joint hypermobility, instability, multi-system symptoms, chronic pain

  • Less common:

    • Classical (cEDS) → stretchable, fragile skin, atrophic scarring, velvety skin texture

      • Vascular (vEDS) → blood vessel fragility (including aneurysm or rupture), organ involvement, pneumothorax (often without marked joint hypermobility)

  • Very rare:

    • Periodontal (pEDS) → early-onset gum disease, gum recession, and tooth loss

    • Kyphoscoliotic (kEDS) → early-onset kyphoscoliosis and muscle weakness

    • Spondylodysplastic (spEDS) → short stature, muscle weakness, limb bowing, and characteristic facial features

    • Brittle Cornea Syndrome (BCS) → corneal fragility, vision changes, and hearing loss

    • Arthrochalasia (aEDS) → severe hypermobility with frequent dislocations, especially in the hips and from a young age

    • Musculocontractural (mcEDS) → congenital contractures and characteristic facial features

    • Classical-like (clEDS) → stretchy, velvety skin without atrophic scarring, often with foot deformities

    • Dermatosparaxis (dEDS) → extremely fragile, loose skin with severe bruising and characteristic facial features

    • Myopathic (mEDS) → muscle weakness and proximal joint contractures

    • Cardiac-valvular (cvEDS) → significant involvement of the heart valves

Marfan syndrome

  • Often involves taller stature, long limbs, fingers and toes, chest differences (such as pectus excavatum), and features affecting the heart and eyes

Loeys-Dietz syndrome

  • May involve wide-set eyes, a cleft palate or bifid uvula, and blood vessel differences

Common patterns may include:

  • Skin → softness, stretch, fragility

  • Joints → instability, injuries, delayed recovery

  • Cardiovascular → heart or blood vessel differences

  • Other features → eyes, facial structure, body proportions

Genetic/Developmental Conditions

Some forms of hypermobility are associated with genetic or developmental conditions that affect how the body develops, moves, and functions over time.

In these cases, hypermobility is often related to factors such as muscle tone, coordination, or overall development, rather than differences in connective tissue structure.

This includes:

Down Syndrome

Fragile X Syndrome

Williams Syndrome

Common patterns may include:

  • Muscle tone → lower muscle tone (hypotonia)

  • Movement → coordination differences or delayed motor development

  • Joints → increased flexibility or joint instability

  • Development → differences in learning, behaviour, or sensory processing

These patterns can also overlap with other forms of hypermobility.

Neuromuscular Conditions

Some forms of hypermobility are influenced by how muscles and the nervous system work together to support and control movement.

In these cases, joints may appear hypermobile, even when connective tissue structure is typical, not because of differences in connective tissue structure, but due to reduced muscle support, coordination, or control.

This may include:

Cerebral palsy

Muscular disorders (such as muscular dystrophies)

Nerve-related conditions (such as peripheral neuropathies)

Common patterns may include:

  • Muscle strength → reduced strength or endurance

  • Movement control → coordination differences or difficulty stabilising joints

  • Joints → instability or increased movement due to reduced muscular support

  • Function → fatigue, difficulty with sustained or controlled movements

These patterns can also overlap with other forms of hypermobility.

Acquired / Secondary Hypermobility

Hypermobility can also develop over time, rather than being present from birth.

In these cases, joint movement may increase due to changes in the body’s structure, stability, or how it is used over time.

In people who are already hypermobile, these factors can further increase joint movement or instability over time.

This may include:

  • Injury or repeated strain → ligament laxity or joint instability following trauma or overuse

  • Physical activity or training → increased flexibility in dancers, gymnasts, or other movement-based activities

    • People with underlying hypermobility are often naturally drawn to these activities due to increased flexibility and movement ability, and participation does not exclude other forms of hypermobility.

  • Hormonal influences → changes in joint stability (for example during pregnancy)

  • Deconditioning → reduced strength or stability over time

  • Inflammatory conditions → changes in joint structure or support (such as rheumatoid arthritis)

Common patterns may include:

  • Onset → changes noticed over time rather than from early childhood

  • Joints → instability or increased movement in specific areas

  • Strength → reduced strength or endurance

  • Function → pain, fatigue, or difficulty with sustained activity

These patterns can also overlap with other forms of hypermobility.

What this means for you

Hypermobility can exist for different reasons — and you don’t need to fit neatly into one category to begin understanding your body.

Often, the focus is less about finding a single label, and more about recognising patterns in how your body responds and what it needs.

From here, the focus becomes:

• recognising your own patterns
• understanding how your body responds
• finding the right support for you