Start here: the system it is asking about
Your autonomic nervous system runs the things you never think about: heart rate, blood pressure, digestion, sweating, temperature, bladder. When it misfires after COVID, the result is dysautonomia, and the symptoms land in several systems at once, which is exactly why they get brushed off individually.
COMPASS-31 was built to capture that scattered picture in one structured instrument, turning a vague, multi-system complaint into a number you can compare over time.
What it measures
The questionnaire scores autonomic symptom burden across domains including orthostatic intolerance, gut, bladder, sweating, and pupils. You complete it yourself, which makes it cheap, repeatable, and usable at home, with no specialized equipment.
In long COVID cohorts, COMPASS-31, often paired with a stand or lean test, has been used to estimate how common dysautonomia is and how heavy the symptom burden runs.1
validated instrumentwell-foundedsymptom score, not a physiology test
What a score does and does not establish
A high score is a strong signal that your autonomic nervous system is contributing to how you feel, and it makes that contribution visible in a way a clinic visit often cannot. It is especially useful for tracking whether things are improving or worsening over time.
The honest boundary is that it measures symptoms, not physiology. A high score supports moving on to objective autonomic testing, such as tilt-table or stand testing, rather than standing in for it. A questionnaire cannot, by itself, prove the mechanism.
What the domains cover
COMPASS-31 is not only about feeling dizzy on standing, and that breadth is the point of using it. It scores several autonomic domains at once, including orthostatic intolerance, gut motility, bladder function, sweating, and pupil and light responses, so it captures the full scatter of a control system that quietly touches almost everything your body does without conscious effort.
Each of those domains, taken alone, is easy for a busy clinic to wave away as stress or coincidence. Gathered into one structured instrument, they form a recognizable autonomic pattern that is much harder to dismiss. The questionnaire's real job is to make that pattern visible as a single number, turning a vague, multi-system complaint that gets brushed off one symptom at a time into something a clinician can actually weigh and act on.
Pairing it with objective tests
On its own, a high score establishes that your autonomic symptom burden is significant; paired with a stand or tilt test, it gains physiological weight. The questionnaire captures how you feel across the day, while the lean test captures what your heart rate and blood pressure actually do in the moments after you stand, when orthostatic problems reveal themselves.
Used together they tell a fuller and more credible story than either alone, and they give you two distinct things to track over time as you try to recover. If your aim is to show a skeptical system that something real is happening, a high symptom score backed by abnormal numbers on standing is far harder to set aside than a questionnaire by itself. That pairing is how the score earns its place as a door-opener rather than a curiosity.
What a score cannot do
The honest limit is that COMPASS-31 measures symptoms, not physiology, so a high score supports moving on to objective autonomic testing rather than standing in for it. A questionnaire, however well-validated, cannot by itself prove a mechanism or pin down which form of dysautonomia you have, and treating it as a diagnosis would overstate what self-report can deliver.
Kept in its proper lane, though, it is one of the most accessible tools available to you, free, repeatable, and usable at home with no equipment. Used well it documents a real burden, justifies further testing, and gives you a baseline to measure against. Used poorly it gets mistaken for the final word, which is exactly the trap to avoid.
What to weigh
Used well, COMPASS-31 is a door-opener: it documents a real burden, justifies further testing, and gives you a baseline to measure against. Used poorly, it can be mistaken for a diagnosis. Keep it in its lane and it is one of the most accessible tools you have.
What we don't know
Honest about the edges of the evidence. These are open questions, not settled answers.
- How tightly the score tracks objective autonomic testing in long COVID specifically.
- Whether it predicts who responds to which treatment.
- How much scores improve as people recover, and on what timeline.
- Where the most useful cutoffs sit for this population, as opposed to the conditions the tool was first validated in.
- Whether repeated self-report drifts over time in ways that complicate tracking.
- How well it captures the autonomic domains that matter most for daily function.
What this means for you
If your autonomic symptoms keep getting taken one at a time and dismissed, completing COMPASS-31 and bringing the score to an appointment can change the conversation. It packages a scattered experience into something a clinician can act on.
Treat a high score as a reason to ask for objective autonomic testing, not as the final word. Its job is to get you through the door to the tests that can show the physiology, and to give you a number you can watch as you try to recover.
References
Each reference links to the source on PubMed, PMC, or the publisher.