Short answer · Medically reviewed summary · Last updated: 2026-04-06
The hallmark symptom of Chronic Fatigue Syndrome / M.E. is post-exertional malaise (PEM), a disproportionate worsening of symptoms following even minor physical or cognitive exertion. Characteristic Symptoms and Early Warning Signs While Chronic Fatigue Syndrome / M.E.
39 people with Chronic Fatigue Syndrome / M.E. have shared their first-person experience on this question at DiseaseMaps.
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Which are the symptoms of Chronic Fatigue Syndrome / M.E.?
Symptoms of Chronic Fatigue Syndrome / M.E. reported by real patients, from the most common to the most limiting, plus a medically reviewed summary with sources.
The hallmark symptom of Chronic Fatigue Syndrome / M.E. is post-exertional malaise (PEM), a disproportionate worsening of symptoms following even minor physical or cognitive exertion.
Characteristic Symptoms and Early Warning Signs
While Chronic Fatigue Syndrome / M.E. presents differently in every patient, the clinical picture is defined by a profound, non-restorative exhaustion that is not alleviated by sleep. Early warning signs often include a sudden onset of "flu-like" symptoms, such as persistent sore throats, swollen lymph nodes, and low-grade fevers. Many patients also report early sensitivities to environmental stimuli like light, sound, or specific chemical odors, which can serve as precursors to a more severe episode of neuroimmune exhaustion.
Symptom Variability and Quality of Life
The severity of Chronic Fatigue Syndrome / M.E. exists on a spectrum; some individuals may remain mobile but with significantly reduced stamina, while others may become housebound or bedbound. Autonomic dysfunction, particularly orthostatic intolerance and POTS (Postural Orthostatic Tachycardia Syndrome), frequently causes dizziness and heart palpitations, which often pose the greatest barrier to daily functioning. The unpredictability of these symptoms—where a patient may feel capable one day and experience a total physical "crash" the next—is a defining, and often isolating, aspect of the disease.
Progression and Medical Oversight
Symptoms of Chronic Fatigue Syndrome / M.E. can fluctuate over months or years. While some patients experience periods of stability, others may see a slow progression or, conversely, a gradual improvement with strict adherence to "pacing"—the careful management of energy expenditure. You should seek immediate medical attention if you experience chest pain, severe shortness of breath, loss of consciousness, or neurological deficits such as sudden paralysis or inability to speak, as these may indicate complications unrelated to or exacerbated by your underlying condition.
Medical Disclaimer: This information is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
References
- NIH Genetic and Rare Diseases Information Center (GARD)
- Orphanet: Portal for rare diseases and orphan drugs
- Solve M.E. (Solve ME/CFS Initiative)
- Centers for Disease Control and Prevention (CDC) - ME/CFS Clinical Overview
Author: DiseaseMaps Editorial Team
Reviewed against authoritative medical sources (NIH GARD, Orphanet, OMIM)
Last updated: 2026-04-06
Sources cited: NIH Genetic and Rare Diseases Information Center (GARD) · Orphanet: Portal for rare diseases and orphan drugs · Solve M.E. (Solve ME/CFS Initiative) · Centers for Disease Control and Prevention (CDC) - ME/CFS Clinical Overview
Medical disclaimer:
This information does not substitute professional medical advice. Always consult your doctor before making health decisions.
Source:
DiseaseMaps.org
Complete exhaustion all the time
Inability to mentally keep up
Chemical, light and sound sensitivities
Need to avoid large groups
Always fighting a cold
Inability to mentally keep up
Chemical, light and sound sensitivities
Need to avoid large groups
Always fighting a cold
Posted Apr 17, 2019 by MEAction of CO
Not having enough Energy
Posted Dec 20, 2019 by ME International
Brain fog and pain. Violent muscle spasms while you try to sleep.
Posted Feb 21, 2017 by Catherine 1002
the fatique
Posted Feb 22, 2017 by Karen Lisa 302
The flu like aching pain all over my body, but especially in my lower extremities and the weakness that confines me to a recliner or the bed are the most limiting symptoms and the ones I would want to get rid of first. Before getting the flu on 12/28/09 I work full-time as an RN and rode a bicycle 200 miles a week for fun! The post exertional malaise (PEM) worsens my condition each time my symptoms remit enough to where I think I can be up and do something as simple as preparing my own meal and folding laundry, I crash! I think the next worst symptom is the constant sweats that leave me drenched and suffering chills. It's a never ending battle all day and my home looks like a Chinese laundry with wet pajamas hanging out to dry!
Posted Apr 6, 2017 by Christina Maria Cooper 350
For me, the worst part of this disease is how it affects my brain. I have trouble concentrating and remembering things. There are times when it feels like a bit of knowledge just falls into a black hole and nothing I can do will retrieve it. Also when I am thinking one thing and suddenly some weird word replaces one of the words I had meant to say. A word that has absolutely nothing to do with what I was trying to say like moon rather than car or something even more bizarre. There are things I can do that don't require a lot of energy, as long as my mind is firing on all cylinders. That is why for me it is the cognitive issues I find the worst.
Posted Apr 7, 2017 by Linda D 352
Chronic fatigue exhaustion weakness chronic pain
Posted Apr 27, 2017 by Miranda 406
Fatigue
Posted May 4, 2017 by Ben 1079
post-exertion malaise, fatigue/exhaustion, pain, orthostatic intolerance, brain fog, shaking, stuttering,
Posted May 4, 2017 by Nicolette 150
Fatigue
Posted May 11, 2017 by Lymie 201
Mental & physical exhaustion
Brain fog
Post exertion burn out
Sick all the time
Brain fog
Post exertion burn out
Sick all the time
Posted May 12, 2017 by missylob 1056
Feeling constantly tired with flu like symptoms as temperature, aches and pains (headache, nausea, tachicardia, dizziness, joint and muscular pain), sense of faint. Post exercize malaise. Long time to recover after work or after a walk ecc.
I would get rid of the permanent tiredness first of all.
I would get rid of the permanent tiredness first of all.
Posted Aug 27, 2017 by Emy 2050
The every day exhaustion just being awake
Posted Aug 30, 2017 by Jaime 800
Post exertion malaise. It's grim, and easy to forget to pace yourself if you're feeling ok. You'll pay for it, though, so pace yourself!
Posted Sep 5, 2017 by Shirley 2050
Dragging exhaustion, pain in my legs, brain fog
Posted Sep 8, 2017 by Sam 1400
Fatigue
Intractable Headache
Tachycardia
Diabetes Insipidus
POTS
Post Exertion Malaise
Loss of normal Cognitive functioning
Low Blood Pressure
Low Blood Volume
Intractable Headache
Tachycardia
Diabetes Insipidus
POTS
Post Exertion Malaise
Loss of normal Cognitive functioning
Low Blood Pressure
Low Blood Volume
Posted Sep 10, 2017 by Sharon 1500
Debiliating fatigue malaise pain exercise intolerance sensitive to light noise chemicals foods a myriad of co mobidities alongside the illness its chronic and many are housebound and bedridden
Posted Jan 17, 2018 by Annette 2500
Mind numbing fatigue
Waking up exhausted
Too much pain to sleep
Tingling all over
Tremors during a crash or flare up
Muscle weakness in my leg making walking difficult or impossible
Forgetfulness
Total memory loss of certain events
Waking up exhausted
Too much pain to sleep
Tingling all over
Tremors during a crash or flare up
Muscle weakness in my leg making walking difficult or impossible
Forgetfulness
Total memory loss of certain events
Posted Jan 18, 2018 by Tars99 1050
Weakness that nothing changes; Fatigue that is disabling and no amount of sleep changes; Super-Sensitivity to light, sound, touch, etc. (ex: wearing dark sunglasses indoors; screaming when the cause is exaggerated to what is normal); Exercise Intolerance causing physical damage rather than any benefit; Cognitive issues which include such symptoms as 20% or less memory retention, brain fog, trouble finding words or being unable to speak at times; Pain of various kinds including random needle pains, pain coming from the base of the skull especially; Sensations of various kinds, seemingly random; Blurred vision.
Posted Mar 2, 2018 by Beti 2700
Endless fatigue
Non-restful sleep
Brain fog
Pain in extremeties especially the legs
Breathless
Loss of strength
Chronic migraine
Non-restful sleep
Brain fog
Pain in extremeties especially the legs
Breathless
Loss of strength
Chronic migraine
Posted Aug 9, 2018 by cathy 2500
Fatigue and weakness are the most limiting symptoms. I would get rid of the fatigue first.
Posted Jan 3, 2019 by Jeannie -400
PENE and PEM and Pain
Neurological impairment and Immune suppression
secondary chronic viral infections including and not limited to: HHV6, Shingles, caEBV, CMV, etc
POTS, OI, and NMH [inability to maintain an upright position, and the consequences of trying to do so]
autonomic dysfunction
secondary thyroiditis due to caEBV
pernicious anemia
IBS
Fibro
TMJ
I could go on for days
and secondary spinal MS
congenital cases of ME
infertility and miscarriage
intractable Migraines
Sensory overload
seizures other than epilepsy
etc
Neurological impairment and Immune suppression
secondary chronic viral infections including and not limited to: HHV6, Shingles, caEBV, CMV, etc
POTS, OI, and NMH [inability to maintain an upright position, and the consequences of trying to do so]
autonomic dysfunction
secondary thyroiditis due to caEBV
pernicious anemia
IBS
Fibro
TMJ
I could go on for days
and secondary spinal MS
congenital cases of ME
infertility and miscarriage
intractable Migraines
Sensory overload
seizures other than epilepsy
etc
Posted Apr 6, 2019 by Fadra 2550
Post Exertional Malaise
Sleeping problems
Severe Fatigue
Cognitive problems
Orthostatic Intolerance, POtS
Pain
Infections
Autonomic problems
Sleeping problems
Severe Fatigue
Cognitive problems
Orthostatic Intolerance, POtS
Pain
Infections
Autonomic problems
Posted Aug 3, 2019 by Jessica 1200
Symptoms of CFS/ME begin with the "chemical flu" or flu-like symptoms caused by a previous exposure (acute or chronic exposure) to toxic chemicals. Flu-like symptoms may not develop until another assault on the immune system--virus, bacterial infection, mold exposure, immunizations, toxic mold exposure, prolonged stress, etc. The chemical flu progresses into more serious symptoms--neurological changes, inflammation issues, other system disfunction.
Posted Dec 12, 2019 by Joanna 6200
The conditions of ME are listed in the ICPrimer. Here is a link to that Primer.https://www.me-international.org/understanding-criteria.html
Posted Dec 21, 2019 by Pam 3550
Most limiting are....Fatigue & brain fog as well as fatigued or painful muscles.
In my case the first to reduce was pins and needles on my feet and hands. Restless legs, temperature control.
I would get rid of the fatigue first. Temperature control next.
In my case the first to reduce was pins and needles on my feet and hands. Restless legs, temperature control.
I would get rid of the fatigue first. Temperature control next.
Posted Mar 11, 2020 by yasmin1 300
EXHAUSTION, physically and mentally all the time. Brain fog. Achy ness everywhere. Weakness. Migraines. Feeling helpless.
Posted Jan 17, 2021 by Emmy 2250
Post Exertional Malaise (the worsening of your symptoms after exertion. This sets in 24-72 hours after exeterion and exertion can be as much as working out to as little as having another person in the room.)
Fatigue
(muscle) pain
Brainfog/cognitive dysfunction
Sleep problems
Fatigue
(muscle) pain
Brainfog/cognitive dysfunction
Sleep problems
Posted Nov 18, 2022 by Arlette 1300
Constant Extreme Exhaustion, Sleep Reversal, Intolerance To Light & Sound, Bad Headaches, Digestive Problems, Swollen Glands, PEM, Brain Function Problems, Chronic Brain Fog.
Posted Jun 25, 2023 by June Johnston 100
Translated from spanish
Improve translation
Extreme exhaustion permanent.
Headache.
Loss/excess smell.
Loss/excess of taste.
Loss/excess of the sense of touch.
Disorientation,
Loss of memory.
Headache.
Loss/excess smell.
Loss/excess of taste.
Loss/excess of the sense of touch.
Disorientation,
Loss of memory.
Posted Feb 24, 2017 by Anabel Albornoz Molinari 1076
Translated from spanish
Improve translation
Tiredness, intolerance to effort and physical exercise, cognitive problems, viral reactivations,
Posted Mar 6, 2017 by Yabisa 700
Translated from french
Improve translation
Fatigue
The state of influenza ; headaches , hot cold, sore throats be sore all over
Memory loss
Fog in the brain
The state of influenza ; headaches , hot cold, sore throats be sore all over
Memory loss
Fog in the brain
Posted Mar 9, 2017 by Edith 1050
Translated from spanish
Improve translation
Tiredness, weakness ortrostatica, headache
Posted May 12, 2017 by Marisa 1000
Translated from spanish
Improve translation
Extreme tiredness, dizziness after sitting for 10 or 15 min of standing, dizziness when getting up... A feeling of having fog in the head q does not goes away.. Clumsiness.. - to not have the strength, you fall over things, periods of insomnia or hypersomnia, pain muscularessin inflammation.. Q give you the hand can aer a torture. Migraine headaches...Depends on the degree in q what you are and each persoma... Tb weight gain or weight loss for no apparent reason. Similar to a flu constant
Posted May 25, 2017 by Cristina 601
Translated from spanish
Improve translation
Not being able to do anything that you want.
Stand up and the 10 steps to fall exhausted.
Do not sleep or rest.
Cold.
Pain.
Do not think about.
Difficulty in the reading.
I would remove the fatigue and to be able to sleep.
Stand up and the 10 steps to fall exhausted.
Do not sleep or rest.
Cold.
Pain.
Do not think about.
Difficulty in the reading.
I would remove the fatigue and to be able to sleep.
Posted Sep 11, 2017 by Eduardo Casasnovas 2950
Translated from spanish
Improve translation
Being tired without previous efforts.headache due to fatigue .
Posted Sep 11, 2017 by Haydee de bielik 5120
Translated from french
Improve translation
Fatique, aches and pains.memory loss,headache ,brain confused
Posted Sep 14, 2017 by Claire 200
Translated from spanish
Improve translation
extreme drowsiness persistent
low body temperature
problems ortostaticos
memory problems
Intolerance to noises and smells and the light
sleep problems
body aches
lack of orientation and coordination
Investment day / night
muscle weakness (dropping things)
eyes dry and irritated
outbreaks of fatigue that prevent getting up for days, weeks, months - or years
Herpes in the mouth, nose, throat - eye(s)
Intolerance to extreme effort
stress can trigger an outbreak
intolerance to chemicals
food intolerance
the symptoms may improve but there is no cure
symptoms such as fatigue must be present for at least 6 months
headaches
.... and more
low body temperature
problems ortostaticos
memory problems
Intolerance to noises and smells and the light
sleep problems
body aches
lack of orientation and coordination
Investment day / night
muscle weakness (dropping things)
eyes dry and irritated
outbreaks of fatigue that prevent getting up for days, weeks, months - or years
Herpes in the mouth, nose, throat - eye(s)
Intolerance to extreme effort
stress can trigger an outbreak
intolerance to chemicals
food intolerance
the symptoms may improve but there is no cure
symptoms such as fatigue must be present for at least 6 months
headaches
.... and more
Posted Oct 19, 2017 by Heidrun Kroner 2000
