Phantosmia in hEDS: Understanding the Mystery of Phantom Smells
A smell that no one else notices can feel surprisingly invasive. Smoke in a clean room. Burnt toast at bedtime. Perfume in an empty hallway. For people with hypermobile Ehlers-Danlos syndrome, or hEDS, phantom smells can be more than a strange sensory glitch. They can raise real questions about the nervous system, inflammation, migraine, and the many overlapping symptoms that often come with connective tissue disorders.
Phantosmia means smelling something that is not present in the environment. It is a type of olfactory hallucination, but that phrase can sound more alarming than the symptom itself. Many cases are linked to common medical issues, such as sinus irritation, migraine, medication effects, or changes after a viral infection.
New, severe, or one-sided smell changes deserve a conversation with a qualified clinician.
How common is phantosmia in hEDS?
The honest answer is that we do not yet know. Phantosmia has been studied in the general population and in conditions such as migraine, sinus disease, epilepsy, Parkinson’s disease, and post-viral smell disorders. It has not been well measured in hEDS specifically.
That means there is no reliable percentage for how many people with hEDS experience phantom smells. Still, clinicians who care for hEDS patients and people in patient communities often hear about smell disturbances alongside other sensory symptoms.
This gap matters. hEDS is not “just flexible joints.” Many people also deal with symptoms involving:
Autonomic dysfunction, including POTS-like symptoms
Migraine or chronic headache
Allergies, rhinitis, or mast cell activation symptoms
Gastroesophageal reflux
Neck instability or cervicogenic headache
Sensory sensitivity and central nervous system hyperarousal
Small fiber neuropathy symptoms, such as burning, tingling, or altered sensation
Any of these may play a role in phantosmia in hEDS, even if research has not yet drawn a clean line between cause and effect.
A phantom smell is not “made up.” The experience is real, even when the source is not in the room.
Why phantom smells may happen in hEDS
Smell depends on several steps working together. Odor molecules reach the olfactory epithelium high in the nose. Nerves send signals to the olfactory bulb. The brain then identifies and gives meaning to the signal.
Phantosmia can happen when one part of that system sends noise instead of a clear message. In hEDS, several possible contributors may overlap.
Migraine activity can affect smell processing
Migraine is common in people with hEDS, and it does not always look like a classic headache. Some people have aura, light sensitivity, nausea, dizziness, or neck pain. Smell changes can appear before, during, or after a migraine episode.
For one person, the phantom odor may be burning plastic. For another, it may be cigarette smoke. The smell may last minutes, hours, or longer. When it appears with light sensitivity, nausea, visual changes, or head pressure, migraine becomes one possible explanation.
Dysautonomia may change sensory thresholds
Many people with hEDS have autonomic nervous system symptoms. These can include rapid heart rate on standing, temperature swings, sweating changes, nausea, faintness, and adrenaline-like surges.
The autonomic nervous system helps regulate blood flow, inflammation, digestion, and alertness. When it runs in an unstable pattern, the brain may become more sensitive to internal signals. A mild odor, nasal irritation, or nerve misfire may feel louder than it would for someone without dysautonomia.
Nasal inflammation can confuse the smell system
Allergies, chronic rhinitis, sinus irritation, and postnasal drip can affect smell. Some people with hEDS also report mast cell activation-type symptoms, such as flushing, itching, hives, congestion, wheezing, or food-triggered reactions.
Inflamed nasal tissue can irritate the olfactory nerves. After a cold, flu, or COVID-19 infection, smell pathways may also recover unevenly. That can lead to distorted smells, reduced smell, or phantom smells.
Neck issues and nerve sensitivity may contribute
Some hEDS patients experience neck pain, cervicogenic headaches, or concerns about upper cervical instability. The neck does not directly create smell, but neck-related pain and nervous system irritation can feed into headache circuits and sensory sensitivity.
Small fiber neuropathy is another possible piece. It affects small sensory and autonomic nerve fibers. While it is better known for pain, burning, tingling, and temperature changes, it shows how nerve signaling can become altered in complex connective tissue conditions.
When to discuss phantosmia with a clinician
It is reasonable to mention phantom smells during a routine visit, especially if they repeat or connect with other symptoms. A few situations call for quicker care.
Seek medical guidance promptly if phantom smells are:
New and sudden
Only on one side
Linked with seizures, confusion, fainting, or weakness
Paired with severe or unusual headache
Present after head injury
Associated with major personality, memory, or vision changes
Persistent after a respiratory infection
Causing distress, poor sleep, or safety checking that disrupts daily life
A clinician may ask about migraine, sinus symptoms, allergies, infections, medications, reflux, dental issues, neurologic symptoms, and environmental exposure. Depending on the pattern, evaluation may involve primary care, neurology, an ENT specialist, or allergy and immunology. Useful details to track include:
What the smell is like
How long it lasts
Whether it affects one nostril or both
Headache, dizziness, nausea, or visual symptoms
Menstrual cycle timing, if relevant
Recent infections or medication changes
Allergies, congestion, reflux, or food triggers
Sleep, hydration, stress, and posture changes
Finding support while answers are limited
One hard part of phantosmia is how isolating it can feel. Smell is private. If no one else senses it, the experience can be dismissed too quickly.
People with hEDS already spend a lot of energy explaining symptoms that do not show on a basic exam. Phantom smells can add another layer of doubt. Clear tracking, calm documentation, and a clinician who takes the symptom seriously can make a real difference.
It may also help to use plain language in appointments:
“I keep smelling smoke when there is no smoke present. It happens three times a week, usually before head pressure and nausea. I have hEDS and POTS symptoms. Could this be related to migraine, sinus inflammation, medication, or another neurologic issue?”
That kind of summary gives the clinician a starting point without forcing a single explanation.
Phantosmia in hEDS is real, under-studied, and often part of a wider symptom pattern. Current research does not tell us how common it is in hEDS patients, but several known hEDS-related issues may help explain why it happens. Migraine, dysautonomia, nasal inflammation, post-viral changes, nerve sensitivity, and medication effects can all play a role.
The most helpful next step is not panic. It is pattern-finding. Track the smell episodes, note related symptoms, and bring the information to a clinician who understands complex chronic conditions. Even when the cause is not obvious right away, the symptom deserves care, curiosity, and respect.
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