Medical Speak
Hypermobility Spectrum Disorders (HSD) are multi-systemic connective tissue disorders that affect different organ systems in the body and result in a wide range of symptoms that include but are not limited to musculoskeletal pain, joint instability, skin and musculoskeletal injuries, fatigue, headaches, problems in gastrointestinal and urogenital systems, autonomic dysfunction, and pain.
English Translation
Hypermobility Spectrum Disorders (HSD) are conditions that affect multiple parts and organs of the body. They result from problems in the body cells that are together known as connective tissue - they hold other cells together.
If the body is compared to a building, then the connective tissue can be compared to all the cement, putty, clamps, screws, bolts, and adhesives used in the building to bind, hold and support all other components like bricks, fittings and fixtures, plumbing, and woodwork.
As you can imagine, in such a situation, everything in the building would malfunction, not just the "joints" between the walls.
The defective connective tissues lead to problems in the functioning of almost every part of the body, resulting in a wide variety of symptoms. The person may run from pillar to post, trying to figure out each separate set of symptoms, assuming them to be separate diseases. They are indeed separate and distinct conditions—be it bowel problems or eye problems or an elbow problem—but they are caused by this common underlying factor.
An Important Question
"Ok, I understand that a defective supporting material in the body can affect the joints. But it seems HSD is a catch-all diagnosis for everything. But how can HSD affect nerves or immunity or such things which don't at all seem connected to the matter of structural strength and support?"
HSD is not a catch-all diagnosis. It cannot be held responsible for a specific disease or dysfunction of any organ system a person has without any involvement of connective tissues. For example, if everything else is normal, HSD cannot be a diagnosis for an isolated kidney disease a person has.
However, if a person has symptomatic levels of a connective tissue disorder, then they can exhibit dozens of symptoms from the head to the toe, for the simple reason that connective tissue is everywhere in the body, and it does not quite work the way it is supposed to, in this individual.
The subluxations and dislocations of joints are well-known in the context of EDS and HSD. EDS itself can be of many types, some of them having life-threatening components. In the context of hypermobility type EDS, and HSD, the common assumption is that the person has increased flexibility, and that is the end of it. This is not true.
Below are some points that may help you to understand what other subtle effects HSD can have in the body, and why. These are based on the combination of human anatomy, cell biology, and findings of research and clinical studies.
The Big Picture: The gross and macroscopic manifestation of the defective connective tissue can be understood as problems with the skin, the soft tissues underlying the skin, in muscles, in joints and joint structures, in ligaments that hold 2 bones together in a joint structure, in tendons that join muscles to the bones, etc. Obviously, problems with these tissues lead to the problems of muscle and soft tissue weakness; joint instability, partial and complete dislocations; fragile and easily injured skin, joints and muscles; etc.
The devil is in the details: The microscopic implication of the defective connective tissue is that it leads to dysfunction of many cells and parts of cells (organelles) and structures surrounding cells. This can lead to improper mobility of cells, dysfunction in communication between cells, problems in structural behavior of and collaboration between cells, etc.
These cells are also in all the walls of blood vessel, leading to abnormal behavior of blood vessels in their roles in maintaining blood pressure, heart rate, body temperature, etc. This may have a role in anxiety problems too.
These cellular structures can influence the way blood cells including the immune cells communicate with each other and other cells.
There can be abnormalities in how signals and responses happen in the cells of the bronchial tubes in the chest, through which air reached the lungs.
There can be malfunctioning in the way cells absorb nutrients from food and push or carry them to blood, which will result in digestive problems.
There can be structural weakness of internal tissues, like the walls of vagina, rectum, bowels, stomach, etc.
There can be abnormal behavior of small nerve fibers that are present throughout the body.
Combined with the nerve fiber problems, the structural resilience problems of internal organ structure walls may lead to disruption in the symphony-like coordinated movements that happen internally for smooth functioning of many systems: evacuation of bowel and emptying of bladder, food moving forward in the stomach and intestines, childbirth, and so on.
The tiny bones in the inner ear responsible for balance may be hypermobile leading to balance problems like vertigo. The sensors we have in legs and joints to sense our position and help our brain keep the balance may malfunction, leading to what is called problems in proprioception.
The combination of lack of coordination between cells and systems, poor responses of the reflexes, poor strength and joint stability, and other factors may lead to an overall coordination problem in the person, called dyspraxia.
The overall lack of muscle strength and/or tone, stability, joint strength, poor blood pressure and temperature management, chronic long-standing pain, and other factors including neurological factors can lead to severe fatigue problems in the person.
The abnormal structural material in the eyes can lead to vision problems.
Not everything is known about how the defective tissues can affect the brain tissue and neurological functions, but is reasonable to assume that it does. Many problems like migraine are frequent in people with HSD. There is also overlap between people having HSD and neurodevelopmental disorders like autism.
The exact mutations of the genes that cause these disorders are not known but it is probable that the mutation has other effects or is associated frequently with other mutations in the neighborhood - on the same chromosome. This may lead to association with other condition that tend to co-exist in the individual with the HSD. Some mechanism like this may underlie the frequent association with anxiety disorders.
The problems of structural weakness includes injuries to and inflammation of soft tissues of joints leading to tenosynovitis, tendinitis, ligamental problems, joint instability, and so on. What is not understood by others is that numerous small but painful problems may also occur like injuries to skin and nails (like nailbed) during routine activities. A heavy blanket may injure the ankles. A sudden gust of wind, lurch in the bus, and hard brakes or swerves in a car- may all lead to a dis-coordinated and inefficient effort of the body to regain balance, and result in joint dislocation, muscle sprain, injury, spasm and severe pain that lasts many days.
To know more about HSD, click on the buttons below:
To know more about why HSD often goes undiagnosed, and find links to research articles on HSD, read our previous post: Hypermobility: a misleading term
If you know someone with HSD or EDS, and you want to understand their experience, you could try joining up on social media groups or blogs on these conditions, even if for just a few weeks. Reading the posts of people who face the consequences of these conditions will provide you with a deeper insight into the helplessness and pain these people battle everyday. It will also allow you to have a greater understanding of how you can help your loved one.
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We hope this article helped you to get a better and simpler view of HSD, and how it affects the body at multiple levels. If you liked this article, share it with others and drop us a comment below!
