Explore Associated Conditions

Gastrointestinal symptoms, such as reflux, abdominal pain, bloating, nausea, constipation, diarrhoea, early fullness and difficulty swallowing, are commonly seen in people with hypermobility.

These symptoms can arise for different reasons.

• Changes in gut–brain interaction: The two-way communication between the nervous system and digestive system can function differently, influencing things like gut sensation, pain and bowel function. Some people may be diagnosed with a disorder of gut–brain interaction, such as irritable bowel syndrome (IBS).

• Changes in gastrointestinal motility: The movement of food and other contents through the digestive tract can also be affected, potentially contributing to symptoms at different stages of digestion.
  

The relationship can be complex. Connective tissue, autonomic function, medications, pain, nutrition and the gut–brain relationship may all contribute differently from person to person.

Migraines, recurrent headaches and neurological symptoms such as neuropathic (nerve) pain, altered sensation and complex pain conditions are common in people with hypermobility.

Head and neck symptoms can have many different contributors. Some conditions you may hear discussed alongside HSD and hEDS include:

• Cervical and craniocervical instability (CCI): Excessive movement or reduced stability through the cervical spine or where the skull and upper cervical spine meet. In some people, this may contribute to neck pain, headaches and neurological symptoms. CCI is an evolving and sometimes controversial area, with diagnostic criteria and evidence still developing.

• Chiari I malformation: A structural condition where part of the cerebellum extends down through the opening at the base of the skull. It can be associated with headaches, neck pain and neurological symptoms.

• Spontaneous intracranial hypotension(SIH)/CSF leak: Loss of cerebrospinal fluid can cause headaches that characteristically worsen when upright and improve when lying down, although presentations can vary.

• Intracranial hypertension: Increased pressure within the skull can also cause headaches and neurological or visual symptoms. 
  

Coat-hanger pain describes an aching or pressure-like pain across the back of the neck and shoulders. It is commonly described in people with orthostatic intolerance and autonomic dysfunction, particularly when symptoms worsen while upright and improve with lying down.

In people with hypermobility, musculoskeletal factors may also contribute to pain through this region. Muscles around the neck and shoulders may work harder to provide stability, contributing to muscular fatigue, tension and protective bracing. For some people, autonomic and musculoskeletal contributors may overlap rather than there being one single cause.

Pelvic and gynaecological symptoms are commonly reported in people with HSD and hEDS. These can include pelvic organ prolapse, urinary and bladder symptoms, pelvic-floor dysfunction, pelvic pain, painful or heavy periods and pain during intercourse.

Connective tissue differences may contribute to some of these presentations, although pelvic symptoms can have many possible causes. Recognising the potential overlap can help ensure pelvic and urogenital symptoms are assessed rather than dismissed as unrelated.

Research increasingly suggests an overlap between joint hypermobility and neurodevelopmental conditions, particularly autism and ADHD. Other neurodevelopmental differences involving learning, communication, coordination and tic disorders have also been explored.

People with EDS and hypermobility also report higher rates of anxiety, depression and other psychological difficulties, although these relationships are complex and don't necessarily indicate a shared biological cause. Living with chronic pain, fatigue, autonomic symptoms, disability and delayed or difficult healthcare experiences may also influence psychological wellbeing.

Mast cells are immune cells involved in allergic and inflammatory responses. Mast Cell Activation Syndrome (MCAS) is a specific condition involving recurrent episodes of inappropriate mast-cell mediator release affecting multiple body systems.

Symptoms can include flushing, itching, hives, swelling, wheezing, rapid heart rate, abdominal cramping, nausea, vomiting and diarrhoea, although these symptoms can also occur for many other reasons.

MCAS is frequently discussed alongside HSD/hEDS and POTS, sometimes referred to as the hEDS–POTS–MCAS triad.

Having allergy-like symptoms doesn't necessarily mean someone has MCAS. Diagnosis requires a characteristic clinical pattern and appropriate medical assessment.