Long COVID (also called Post-Acute Sequelae of SARS-CoV-2 / PASC) refers to new, returning, or ongoing health problems that persist 3 or more months after a SARS-CoV-2 infection, as defined by the WHO. Symptoms may be continuous or relapsing and remitting.
ME/CFS (Myalgic Encephalomyelitis / Chronic Fatigue Syndrome) is a serious, long-term illness that affects many body systems. Long COVID and ME/CFS share striking biological and symptomatic overlap. Many Long COVID patients meet the clinical criteria for ME/CFS.
Long COVID can follow any COVID-19 infection, regardless of severity. Studies show approximately 10-30% of non-hospitalised COVID cases develop Long COVID. It affects all ages, including children, and was more common before widespread vaccination, though vaccinated individuals are not immune. Female sex, older age, pre-existing conditions, and more severe initial illness increase risk.
ME/CFS is not new , it has been documented since the 1950s. Long COVID has brought renewed scientific attention to ME/CFS, as many Long COVID patients develop a condition clinically indistinguishable from ME/CFS. Shared features include PEM, cognitive dysfunction, orthostatic intolerance, immune abnormalities, and sleep disruption.
Long COVID and ME-CFS patients are often left piecing things together across scattered research, social posts, and fragmented advice. This portal is built to centralise the evidence; Recalibrate is the broader ecosystem for turning that understanding into practical navigation and support.
What this portal gives you
PEM guidance, pacing support, treatment evidence, live PubMed updates, clinical trials, and specialist resources in one place.
What Recalibrate adds
A wider home for people navigating complex chronic illness, symptom burden, and the day-to-day reality of living with post-viral health change.
Central Sensitisation
Sensory amplification, pain processing changes, and nervous-system threat patterns may overlap. Open CSS portal →
Fibromyalgia
Many patients move across diagnostic boundaries involving pain, fatigue, and hypersensitivity. Open Fibromyalgia portal →
ADHD / Neurodivergence
Executive dysfunction, sensory load, burnout, and pacing challenges can overlap. Open ADHD portal →
Recalibrate ecosystem
Explore broader support at recalibratepain.com →
Live feed from PubMed. Updates automatically. Browse PubMed directly
Verify eligibility at ClinicalTrials.gov
Long COVID and ME/CFS are complex, multi-system conditions. Current research points to several overlapping biological mechanisms, often occurring simultaneously.
Viral Persistence
SARS-CoV-2 reservoirs may persist in tissue (gut, lymph nodes, brain) long after acute infection, driving ongoing immune activation and inflammation.
Immune Dysregulation
Abnormal T-cell and B-cell responses, elevated inflammatory cytokines, and activated immune signatures persist months to years post-infection.
Microbiome Disruption
COVID-19 and Long COVID are associated with significant gut dysbiosis, which correlates with symptom severity and may perpetuate systemic inflammation.
Autoimmunity
Novel autoantibodies targeting the nervous system, blood vessels, and other tissues have been identified in Long COVID patients, suggesting autoimmune components.
Endothelial Damage
Microclots (microthrombi) and endothelial dysfunction impair oxygen delivery to tissues, contributing to fatigue, breathlessness, and cognitive symptoms.
Mitochondrial Dysfunction
Impaired energy production at the cellular level , mitochondria fail to produce ATP efficiently, explaining profound fatigue and PEM.
Latent Virus Reactivation
EBV (Epstein-Barr Virus), HHV-6, and other herpesviruses may reactivate post-COVID, compounding immune burden and symptoms.
Neurological Involvement
Neuroinflammation, blood-brain barrier disruption, and reduced cerebral blood flow contribute to brain fog, cognitive impairment, and autonomic dysfunction.
Routine blood panels, MRI, and ECG frequently appear normal in Long COVID and ME/CFS patients. This does not mean nothing is wrong. The abnormalities are often at the cellular, mitochondrial, or microbiome level, or involve subtle immune signatures not captured by standard clinical tests. Specialised research assays detect consistent abnormalities , the absence of a positive test result does not invalidate symptoms.
This tool helps identify Post-Exertional Malaise , the hallmark feature of ME/CFS and Long COVID. It is not a diagnostic tool. Share results with your doctor.
1. After physical activity (e.g. walking, housework, exercise), do you feel worse than before?
2. Does this worsening occur 12-48 hours after activity rather than immediately?
3. After mental effort (reading, conversation, screen time), do you experience increased symptoms?
4. How long does it take to recover after a "crash" or worsening episode?
5. Do you need to significantly limit activities to avoid worsening your symptoms?
6. Does exertion cause symptoms beyond fatigue (e.g. pain, brain fog, flu-like feeling, dizziness)?
7. Has "pushing through" fatigue ever made you significantly worse for days or longer?
8. Do emotional or sensory stimuli (stress, noise, light) also trigger symptom worsening?
Evidence grades: A Strong · B Moderate · C Emerging · D Limited · CONTRAINDICATED
| Treatment | Evidence | Notes |
|---|---|---|
| Pacing / Energy Management | A | Staying within energy envelope to avoid PEM. Most important management strategy. Includes cognitive and emotional pacing, not just physical. |
| Heart Rate Monitoring | A | Keeping HR below anaerobic threshold (typically 55-60% max HR) to prevent PEM. Proven to reduce crashes. |
| POTS Management | B | Increased fluid/salt intake, compression garments, beta-blockers, ivabradine, or fludrocortisone depending on subtype. Consult cardiologist/dysautonomia specialist. |
| Antihistamines (H1+H2) | B | Loratadine, cetirizine (H1) with famotidine (H2). Particularly helpful in patients with MCAS overlap. Many report significant symptom improvement. |
| Low-Histamine Diet | B | Reduction in high-histamine and histamine-liberating foods. Beneficial in MCAS subgroup. Reduces immune activation. |
| Low Dose Naltrexone (LDN) | B | 1.5-4.5mg nightly. Anti-neuroinflammatory. Growing evidence base, significant patient-reported benefit. Well-tolerated. Off-label use. |
| SSRIs / SNRIs | B | Particularly for dysautonomia, POTS, and neuropathic symptoms. Fluoxetine, duloxetine. Not purely antidepressant , target autonomic dysfunction. |
| Melatonin | B | 0.5-5mg for sleep disruption and circadian dysregulation. Anti-inflammatory properties may have additional benefit. |
| Antivirals (Paxlovid / Nirmatrelvir) | C | Case series and trials suggest benefit in patients with viral persistence. Research ongoing. Not yet standard of care but promising. |
| BC007 | C | Aptamer targeting autoantibodies. Phase II trials underway. Early results promising for autoantibody-mediated subgroup. |
| Hyperbaric Oxygen Therapy | C | Israeli RCT showed improvements in cognitive function and quality of life. Mechanism may involve neuroplasticity and oxygen delivery. |
| Graded Exercise Therapy (GET) | CONTRAINDICATED | Shown to cause harm in ME/CFS and Long COVID with PEM. NICE guidelines updated 2021 to remove recommendation. Do not use in PEM patients. |
| Cognitive Behavioural Therapy (CBT for deconditioning) | CONTRAINDICATED | CBT based on the discredited deconditioning model is harmful. Psychological support is beneficial but must not promote pushing through PEM. |
Pacing and Energy Envelope
- Identify your energy limit and stay inside it
- Stop activity before you feel tired, not after
- Include cognitive and emotional exertion in your budget
- Use a 1-10 symptom diary to track patterns
- Rest does not mean sleep , quiet lying down counts
Heart Rate Management
- Use a HR monitor (smartwatch or chest strap)
- Stay below anaerobic threshold (approx. 110 bpm or 55% max HR)
- Stop activity immediately if HR rises above threshold
- Lie flat if feeling post-exertional worsening
- Tilt table / recline more to manage POTS symptoms
Cognitive Pacing (Brain Fog)
- Screen time is exertion , limit in acute periods
- Use voice notes instead of writing when fatigued
- Break tasks into very small steps with rest in between
- Prioritise ruthlessly , not everything needs doing today
- Cold packs on the neck can temporarily reduce brain fog
Sleep and Rest
- Unrefreshing sleep is a core symptom , not laziness
- Consistent sleep/wake times help stabilise circadian rhythm
- Avoid screens 1 hour before bed
- Dark, cool room reduces sensory load during sleep
- Melatonin (0.5-5mg) may help circadian dysregulation
Nutrition and Supplements
- Anti-inflammatory diet: reduce processed foods, sugar
- Low-histamine diet if MCAS symptoms present
- Electrolytes (increased salt/fluid for POTS)
- Coenzyme Q10, magnesium, B vitamins (supportive evidence)
- Avoid alcohol , worsens nearly all Long COVID symptoms
Work and Social Adjustments
- Request reasonable adjustments from employer
- Working from home reduces commute exertion significantly
- Part-time or reduced hours during recovery phase
- Communicate energy limits clearly to family and friends
- Disability benefits may be available , seek welfare advice
e.g. age 35: ~102 bpm limit
Join the Community
Connect with others navigating Long COVID and ME/CFS worldwide.
💬 Join Telegram Community 🏥 RecalibrateFree forever. No ads. No data selling.