If you have arrived here from a search or from elsewhere on the site, you may not be sure which of the available tools is most relevant to you. This page is a brief guide to help you decide.
If your main concern is autonomic symptoms
If your main concern is autonomic symptoms (dizziness on standing, heart racing, temperature regulation problems, or gut dysfunction), start with the COMPASS-31. It is the most comprehensive autonomic symptom questionnaire available and gives you a structured, scored summary of symptom burden across six domains. It is particularly likely to be recognised by a specialist if you bring results to an appointment. It takes about 10 minutes.
If breathlessness is a significant symptom
The Nijmegen questionnaire screens for breathing pattern disorder and hyperventilation syndrome, a common and often underdiagnosed problem in post-viral conditions that can contribute to breathlessness, dizziness, brain fog, and chest tightness. It takes about 2 minutes. The Self-Evaluation of Breathing Questionnaire (SEBQ) asks only about breathing sensations and picks up the restricted, effortful, upper-chest patterns the Nijmegen misses; respiratory physiotherapists often use both. It takes about 5 minutes.
→ Nijmegen questionnaire · SEBQ
If fatigue is dominating your life
Two well-established scales measure different things. The Chalder Fatigue Scale asks how much your physical and mental fatigue have changed compared with when you were last well; it is the standard in UK ME/CFS and long COVID services and trials, so it is the score a UK clinic is most likely to recognise. The Fatigue Severity Scale (FSS) measures how much fatigue interferes with daily functioning and is more common in neurology and US research. Each takes about 2 minutes.
→ Chalder Fatigue Scale (UK standard) · Fatigue Severity Scale
If brain fog is your main complaint
The Cognitive Failures Questionnaire counts how often everyday lapses of memory, attention, and action have happened over the past six months. It is the most widely used self-report measure of cognitive slips and is increasingly used in long COVID research to quantify brain fog. It takes about 5 minutes and gives a total out of 100 with reference values.
→ Cognitive Failures Questionnaire
If you suspect ME/CFS, or your symptoms worsen after activity
The feature that most distinguishes ME/CFS from ordinary fatigue is post-exertional malaise: symptoms flaring in the hours or days after physical or mental effort. If that pattern sounds familiar, start with the DSQ-Brief, a 4-question screen (fatigue, tiredness after minimal exercise, unrefreshing sleep and memory problems) that takes under two minutes. To look at the post-activity pattern in detail (triggers and recovery time), the DSQ-PEM takes about three minutes. For a thorough record to take to an appointment, the full DSQ-2 asks all 79 of its symptom questions and checks your answers against the four major ME/CFS case definitions using DePaul's published rules. It is long, about 100 answers, and your progress is saved as you go.
→ DSQ-Brief (quick screen) · DSQ-PEM (post-exertional malaise) · DSQ-2 (full questionnaire)
If you want to check for excessive daytime sleepiness
The Epworth Sleepiness Scale measures your tendency to doze in everyday situations. Fatigue and sleepiness are not the same thing; a low ESS score alongside severe fatigue can be informative in itself. It takes about 2 minutes.
If you want to measure your functional capacity
Three tools at three levels of detail. The Bell CFIDS Disability Scale gives you a single score from 0 to 100 in under a minute, so it suits regular tracking. The Post-COVID-19 Functional Status scale grades the impact on your daily life from 0 to 4 via four quick questions; it is the standard measure in long COVID research. The FUNCAP questionnaire, developed by and for people with ME/CFS, profiles what 27 specific activities cost you. It is the most detailed of the three and the most useful for disability paperwork.
→ Bell scale (quickest) · PCFS (long COVID standard) · FUNCAP (most detailed)
If you suspect POTS or orthostatic intolerance
The NASA lean test guide walks you through an at-home standing test with a timer and heart rate logging. It is a practical way to gather objective data while waiting for formal autonomic testing, and the results can be useful to bring to appointments. Three symptom scores cover different time frames. The Vanderbilt Orthostatic Symptom Score (VOSS) is rated right now while standing, so it belongs at the end of a lean test. The Malmö POTS Symptom Score (MAPS) covers the past week and is the first score designed specifically for POTS. The Orthostatic Grading Scale (OGS) grades your usual pattern in five questions and suits a monthly baseline.
→ NASA lean test guide · VOSS (while standing) · Malmö POTS score (past week) · Orthostatic Grading Scale (usual pattern)
If you or a clinician have raised hypermobility
Start with the Beighton score, the illustrated nine-point test of today's joint range. The five-part questionnaire takes under a minute and captures hypermobility you used to have, which matters if you are older or injured. If hypermobile Ehlers-Danlos syndrome is the question, the hEDS criteria checker walks through all three of the 2017 criteria and shows which items can only be settled by a doctor.
→ Beighton score · Five-part questionnaire · hEDS criteria checker
If you want the big picture: quality of life and well-being
The RAND-36 (the same 36 items as the SF-36) measures health-related quality of life across eight scales. It is used in research across almost every condition, so your profile can be compared with published ME/CFS and long COVID cohorts. It takes 5–10 minutes and suits occasional use, every few months. The WHO-5 Well-Being Index is the opposite trade-off: five questions, under a minute, sensitive to change, and well suited to monthly tracking.
Two shorter scales look at the same picture from different angles. The Satisfaction with Life Scale asks for a considered judgement of your life as a whole, with no time frame, so it is more stable than the WHO-5 and shows adjustment over months. The Brief Resilience Scale measures how quickly you recover from stress, which a dysregulated system does slowly; it is a capacity measure rather than a symptom measure, and it moves when load and support change.
→ RAND-36 health survey · WHO-5 Well-Being Index · Satisfaction with Life Scale · Brief Resilience Scale
If you want a record of your activity level
Neither of these is a target, and in a condition with post-exertional malaise a "low" result is often the right one. They are for recording what you actually did, so that changes in capacity are visible and a clinician sees your real activity rather than a guess. The IPAQ short form covers the last 7 days in detail, including walking and sitting time, and gives MET-minutes per week. The Godin-Shephard questionnaire takes a minute and counts only leisure-time exercise sessions, which makes it quick to repeat weekly.
→ IPAQ short form (detailed, includes sitting) · Godin-Shephard (one minute)
If you want an honest look at alcohol
Alcohol worsens sleep, lowers overnight HRV and pulls fluid, which works against everything a post-viral or orthostatic condition needs, and many people find their tolerance collapses. Others lean on it to sleep or cope. The AUDIT is the WHO's ten-question screen used across the NHS; it gives a score out of 40 with the risk zones and shows whether consumption, dependence or harm is driving it. Two minutes, and worth doing before starting any new medication.
→ AUDIT alcohol screening test
Using more than one
You can complete more than one. For someone with a post-viral condition, a reasonable starting set might be the COMPASS-31 (autonomic symptoms), the FSS (fatigue impact), and the NASA lean test (orthostatic heart rate). Together, these give a fairly rounded picture of the areas most commonly affected.