Related Conditions

Conditions Linked to Hypermobile EDS

hEDS affects the connective tissue that holds the body together — joints, blood vessels, skin, and organs. Because this tissue is present throughout the body, hEDS often occurs alongside other conditions. 

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Autonomic Nervous System

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This is the part of the body that manages automatic functions such as heart rate, blood pressure, digestion, and temperature. In hEDS, this system doesn't always function as expected.

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Dysautonomia (General)

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• This term describes irregularities in the autonomic nervous system that don't always fit a specific diagnosis.

• Signs: dizziness or lightheadedness, difficulty regulating body temperature, abnormal sweating, and digestive or bladder irregularities.

• Why it occurs: stretchier-than-typical connective tissue can affect the nerves and blood vessels this system relies on.

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POTS

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• POTS (Postural Orthostatic Tachycardia Syndrome) means the heart rate rises abnormally upon standing.

• Signs: a racing heart, dizziness, lightheadedness, and fatigue after standing.

• Why it occurs: looser blood vessels make it harder for the body to maintain normal blood flow when changing position. Roughly six in ten people with POTS also meet criteria for hEDS or a related condition.

Immune System

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MCAS (Mast Cell Activation Syndrome)

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• Mast cells are immune cells that release chemicals such as histamine — the same chemical involved in allergic reactions. In MCAS, they are triggered too easily.

• Signs: flushing, itching, hives, digestive upset, or nasal congestion, often triggered by heat, exercise, stress, or certain foods.

• Why it occurs: mast cells reside throughout connective tissue, so a body-wide difference in that tissue may make them more reactive.

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Note: hEDS, POTS, and MCAS frequently occur together — sometimes referred to as "the trifecta." This pattern is well recognized clinically, though researchers are still working out exactly why these three conditions are connected.

Brain and Spine

Craniocervical Instability (CCI)

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• This occurs when the ligaments connecting the skull to the spine are looser than typical.

• Signs: severe headaches and neck pain, a heavy or unstable feeling in the head, dizziness, blurred vision, ringing in the ears, and brain fog.

• Why it occurs: the same ligament laxity responsible for joint hypermobility elsewhere can also affect the neck.

Chiari Malformation and Tethered Cord Syndrome

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• Both involve the brain or spinal cord not being positioned as expected.

• Signs: lower back pain, balance difficulties, leg weakness, or bladder and bowel issues (tethered cord); symptoms often overlap with those of CCI.

• Why it occurs: loose connective tissue can affect the structures supporting the spinal cord. These conditions are less common than POTS or MCAS and typically require specialized imaging to diagnose.

Joints and Muscles

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TMJ (Jaw) Dysfunction

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• The jaw is a joint like any other, so it can be affected by the same hypermobility seen elsewhere in the body.

• Signs: jaw pain, clicking, locking, or difficulty chewing.​​​

Digestive System

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The gut contains substantial connective tissue and its own nervous system, so it is frequently affected.

Slow digestion

• Food moves through the gut more slowly than typical, which can cause bloating, nausea, or irregular bowel habits.

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Reflux and swallowing difficulty: 

• Heartburn and trouble swallowing occur more frequently in hEDS.

Pelvic and Bladder

Pelvic floor dysfunction

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• Looser tissue can make it harder for the pelvic floor to support pelvic organs, sometimes resulting in prolapse or incontinence.

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Bladder pain

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• Chronic bladder pain and frequent urinary urgency occur more often in hEDS.

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Endometriosis

• Many people with hEDS also have endometriosis, and the two conditions share symptoms such as pelvic pain and painful periods. The evidence for a direct biological link is mixed, however — some studies find a higher prevalence, while others do not find a significant association. Because the symptoms overlap so closely, one condition is sometimes mistaken for the other.

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Other Common Conditions

Chronic pain

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• Chronic pain is common in hEDS, often stemming from repeated joint injuries or from the body's pain-processing system becoming more sensitive over time.

• Signs: widespread aching, fatigue, poor sleep, and pain that seems disproportionate to any single injury. This closely resembles fibromyalgia, even though the underlying cause is connective tissue laxity.

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Migraine

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• Headaches tend to occur more frequently and with greater severity

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Raynaud's phenomenon

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• Fingers or toes turn white or blue in response to cold or stress.

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Sleep difficulties

• Trouble falling or staying asleep, often worsened by pain or autonomic symptoms.

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Persistent fatigue

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• Profound, disproportionate tiredness that overlaps with ME/CFS (chronic fatigue syndrome).

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Anxiety and mood changes

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• Living with a complex, often invisible condition is genuinely difficult. Researchers are also examining whether the nervous system itself contributes to anxiety-like symptoms in hEDS — this appears to be a two-way relationship, not an indication that the physical symptoms are simply psychological.

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