Post-Acute COVID-19 Syndrome (PACS)

Post-Acute COVID-19 Syndrome (PACS)—also called Long COVID and PASC (post-acute sequelae of SARS-CoV-2 infection). This is the name most guidelines and journals use for the condition in which symptoms continue or return after a COVID-19 infection.

Post-Acute COVID-19 Syndrome is a chronic condition that appears after a person has had COVID-19. The World Health Organization defines it as new, ongoing, or returning symptoms that start usually about 3 months from the original infection, last at least 2 months, and cannot be explained by another diagnosis. These symptoms commonly include tiredness, shortness of breath, and problems with memory or thinking (“brain fog”), and they interfere with daily life. World Health Organization

Post-Acute COVID-19 Syndrome (also called post-COVID-19 condition or Long COVID) means new or ongoing symptoms that appear after a SARS-CoV-2 infection, usually within 3 months of the initial illness, last at least 2 months, and cannot be explained by another diagnosis. Common problems include fatigue, shortness of breath, and “brain fog,” and they can limit normal daily activities like work, school, or home tasks.

Public-health guidance in the UK (NICE) divides the time course into: acute COVID-19 (up to 4 weeks), ongoing symptomatic COVID-19 (4–12 weeks), and post-COVID-19 syndrome (12+ weeks)—the latter two phrases are often grouped as “long COVID.” NICE

U.S. guidance (CDC) now summarizes Long COVID as a chronic condition present for ≥3 months after infection, with symptoms that can fluctuate or persist and may involve multiple organ systems. CDC+1

Other names

This condition is known by several names in research and clinics. The most common are Long COVID, Post-Acute COVID-19 Syndrome (PACS), Post-Acute Sequelae of SARS-CoV-2 infection (PASC), and Post-COVID-19 condition or Post-COVID Conditions (PCC). These terms all describe the same broad problem: health effects that continue after the acute infection has resolved. World Health Organization+1

Types

Doctors and guidelines group PACS by time and by dominant symptom pattern:

1. By time since infection.
   • Ongoing symptomatic COVID-19: symptoms from 4 to 12 weeks after the start of illness.
   • Post-COVID-19 syndrome: symptoms lasting 12 weeks or more. These labels help plan follow-up and testing. NICE

2. By dominant clinical pattern (phenotype). These patterns often overlap:
   • Fatigue- and PEM-dominant: daily fatigue with post-exertional malaise (worsening hours to days after physical or mental effort), similar to what is seen in ME/CFS. It can limit work, school, and exercise. Nature
   • Cardiopulmonary: shortness of breath, chest tightness, reduced exercise capacity, sometimes with abnormal lung gas-exchange or scarring on imaging. PubMed Central+1
   • Dysautonomia/POTS-like: dizziness, fast heart rate on standing, palpitations, “head rush,” and exercise intolerance due to autonomic nervous system dysfunction. Tilt-table tests can confirm POTS in a subset of patients. JACC+1
   • Neurocognitive (“brain fog”): problems with attention, memory, word-finding, and sleep, sometimes with headaches and mood symptoms. Nature
   • Multisystem: GI upset, altered smell or taste, joint or muscle pain, menstrual changes, skin rashes, and others. Guidelines stress ruling out other causes and targeting tests to the symptom pattern. NCBI

Causes

PACS seems to arise from several overlapping biological mechanisms plus clinical risk factors. No single cause fits everyone. Researchers have proposed and observed the following contributors:

1. Immune dysregulation. After infection, parts of the immune system stay over-active or mis-timed, which can keep inflammation going and delay recovery. Nature

2. Viral persistence. Small amounts of viral material may persist in tissues in some people, continuing to “poke” the immune system and sustain symptoms. Nature

3. Autoimmunity. The immune system may create antibodies that mistakenly target the body’s own tissues, producing chronic symptoms. Nature

4. Microclots and endothelial dysfunction. Tiny clots and blood-vessel lining injury can reduce oxygen delivery and cause fatigue, breathlessness, and brain fog. Nature

5. Mitochondrial energy problems. Inflammation and immune changes may disturb cellular energy production, contributing to exercise intolerance and PEM. Nature

6. Autonomic nervous system dysfunction (dysautonomia). Infection and immune activation can disrupt the body’s automatic controls of heart rate and blood pressure, causing POTS-like symptoms. JACC

7. Small-fiber neuropathy. Damage to small nerve fibers may produce pain, tingling, temperature sensitivity, and dysautonomia symptoms. Nature

8. Persistent lung diffusion abnormality. Some people have reduced DLCO (impaired gas exchange) after COVID-19, which can cause breathlessness during activity. Nature

9. Residual lung inflammation or scarring. Inflammation and fibrosis on CT can follow pneumonia and relate to ongoing cough or breathlessness. PubMed Central

10. Cardiac involvement. Inflammation of the heart muscle or lining or rhythm instability can lead to chest pain, palpitations, and reduced exercise capacity. CDC

11. Microbiome disruption. Changes in gut bacteria after infection and antibiotics may contribute to GI symptoms and systemic inflammation. Nature

12. Reactivation of latent viruses (e.g., EBV). Stress on the immune system may let dormant viruses “wake up,” worsening fatigue and neurocognitive issues. Nature

13. Coagulation pathway activation. COVID-19 can disturb clotting; lingering abnormalities may perpetuate symptoms in some people. Nature

14. Hormonal and endocrine effects. Illness can temporarily disturb thyroid or adrenal signaling, which may add to fatigue or mood changes. Clinicians check for these as alternative or contributing causes. NCBI

15. Sleep disturbance. Insomnia and fragmented sleep after illness can magnify fatigue, brain fog, pain sensitivity, and mood symptoms. NCBI

16. Deconditioning. Weeks of illness and reduced activity can weaken muscles and heart-lung fitness, which worsens breathlessness and fatigue, especially if exercise is not paced. NCBI

17. Psychological stress and mood disorders as comorbidities. Anxiety and depression can coexist with PACS and can amplify perceived symptom burden; treating them helps overall recovery but does not mean symptoms are “all in the head.” NCBI

18. Severity of the acute infection (risk factor). Hospitalization or severe pneumonia increases risk of long-term effects, though even mild cases can develop PACS. PubMed Central

19. Demographic and medical risk factors (risk factors). Studies report higher rates with older age, female sex, and pre-existing conditions such as asthma, diabetes, or autoimmune disease. CDC+1

20. Re-infection and vaccination status (contextual factors). Re-infection may add risk for ongoing symptoms; vaccination reduces the risk of developing Long COVID at the population level, though evidence for using vaccination as a treatment for existing Long COVID is uncertain in NICE analyses. CDC+1

Symptoms

People can have one symptom or many. Symptoms can wax and wane. Common ones include:

1. Fatigue: a heavy, persistent tiredness not relieved by sleep that limits daily tasks. CDC

2. Post-exertional malaise (PEM): feeling much worse hours or days after physical or mental effort—more fatigue, pain, and brain fog—with a slow recovery. Nature

3. Shortness of breath: a feeling of needing more air or getting winded easily, sometimes linked to reduced lung diffusion capacity. Nature

4. Chronic cough or throat irritation: lingering airway sensitivity after infection. NCBI

5. Chest pain or tightness: can be musculoskeletal or related to the heart or lungs; clinicians rule out urgent causes. NCBI

6. Palpitations and fast heartbeat on standing: a racing heart, sometimes from POTS or other rhythm issues. JACC

7. Dizziness or light-headedness: especially on standing up or during showers, linked to dysautonomia. JACC

8. Brain fog: trouble focusing, remembering, or processing information; tasks feel slower or harder. Nature

9. Headache: frequent or new patterns of headache after infection. NCBI

10. Sleep problems: insomnia, unrefreshing sleep, or altered sleep–wake cycles. NCBI

11. Muscle or joint pain: aching, stiffness, or soreness with light activity. NCBI

12. Loss or change of smell or taste: can linger and slowly improve over months. NCBI

13. Anxiety or low mood: can arise from the illness itself and the stress of living with chronic symptoms. NCBI

14. Gastrointestinal symptoms: nausea, diarrhea, abdominal pain, or poor appetite. NCBI

15. Exercise intolerance: inability to reach previous fitness levels without worsening symptoms, sometimes measurable on walk or sit-to-stand tests. NICE

Diagnostic tests

There is no single test that proves PACS. Clinicians start with a good history and exam. They rule out other diagnoses and target tests to the person’s most troubling symptoms. The choices below are common and should be individualized. NCBI

A) Physical exam

1. Orthostatic vital signs. Your pulse and blood pressure are measured lying down and again after standing. A large jump in heart rate or a drop in blood pressure can point to dysautonomia or POTS-like problems. This is simple and quick in the clinic. Tilt-table testing may be used if this is abnormal or symptoms are strong. JACC

2. Pulse oximetry at rest. A finger sensor checks oxygen saturation while you are sitting and breathing quietly. In PACS, resting oxygen is often normal; if low, doctors look for a lung or heart cause that needs urgent care. NCBI

3. Focused heart-lung-neurologic exam. The clinician listens to the heart and lungs; checks swelling, calf tenderness, or chest wall pain; and does a brief neurologic screen (gait, strength, reflexes, sensation) to look for other illnesses that can mimic PACS. NCBI

B) Manual / functional tests

4. 6-Minute Walk Test (6MWT). You walk back and forth for six minutes while staff record distance, breathing, heart rate, and oxygen saturation. It shows endurance and whether oxygen drops with exertion. Some PACS patients show early breathlessness or desaturation. cebm.net

5. 1-Minute Sit-to-Stand Test (1MSTS). You stand up and sit down repeatedly for one minute, with heart rate and oxygen monitored. It is easier to do in a small room and correlates with the 6MWT for detecting exertional oxygen drops. NICE suggests this when appropriate, following safety protocols. NICE+1

6. Active stand test (bedside). While lying and then standing for several minutes, the clinician watches heart rate and blood pressure changes. A rise of ≥30 beats per minute within 10 minutes of standing (without a big BP drop) supports POTS in adults. This can guide whether to order tilt-table testing. JACC

7. Pulmonary function tests with DLCO. Breathing into a machine measures airflow and diffusing capacity (DLCO)—how well oxygen moves from lungs into blood. Reduced DLCO is a common long-COVID finding and can explain exertional breathlessness. Nature

8. Hand-grip or simple strength/endurance measures. These quick checks track deconditioning or muscle involvement and help design a safe, paced rehab plan. Guidelines encourage functional assessment tailored to the person. NCBI

C) Lab and pathological tests

9. Complete blood count (CBC). Looks for anemia or infection that could explain fatigue or breathlessness. Normal results support a functional rather than structural cause. NCBI

10. Inflammation markers (CRP/ESR). A high value may show ongoing inflammation or another condition needing attention; many PACS patients have normal results. NCBI

11. Thyroid function tests (TSH ± free T4). Thyroid problems can mimic fatigue, brain fog, and palpitations; checking these helps avoid missing a treatable cause. NCBI

12. Cardiac enzymes and natriuretic peptides (troponin, BNP/NT-proBNP) when chest symptoms are concerning. These help detect heart injury or strain that requires cardiology care. NCBI

13. Coagulation-related markers (e.g., D-dimer) when indicated. If there is chest pain, calf pain, or sudden breathlessness, clinicians may check for clot risk; abnormal results can trigger imaging for pulmonary embolism. NCBI

14. Selected nutritional and autoimmune screens (e.g., ferritin, B12, vitamin D; targeted autoantibodies when red flags). These are not PACS “proof” tests, but they find treatable contributors to fatigue, neuropathy, or pain in the right context. NCBI

D) Electrodiagnostic / cardiopulmonary physiology

15. 12-lead ECG and ambulatory rhythm monitoring. These record heart rhythm at rest and over 1–14 days to capture palpitations, inappropriate sinus tachycardia, or other arrhythmias. Findings can guide meds and rehab pacing. CDC

16. Head-up tilt-table test (HUTT). You are secured to a table that tilts upright while heart rate and blood pressure are tracked. A large heart-rate rise without blood-pressure drop supports POTS, which has been documented in many people with PACS. JACC+1

17. Cardiopulmonary exercise testing (CPET), when available. This controlled treadmill or bike test measures oxygen uptake and heart-lung performance. In selected PACS cases, it can show reduced aerobic capacity and help tailor safe activity plans (especially when PEM is present). NCBI

E) Imaging tests

18. Chest X-ray. A fast first look for pneumonia scars, fluid, or other lung problems. Many PACS patients have normal X-rays even with symptoms; if symptoms persist, more detailed tests may follow. NCBI

19. High-resolution chest CT. Gives a close look at lung tissue. Some people show ground-glass changes or fibrosis months after infection; others have normal CTs despite symptoms. CT helps explain breathlessness or cough that do not improve. PubMed Central

20. Echocardiogram (heart ultrasound) and brain MRI when indicated. Echo checks pump function, valves, and pericardium if there is chest pain or breathlessness. Brain MRI is ordered for significant neurologic “red flags.” Imaging is chosen based on the person’s presentation rather than done routinely for everyone. NCBI

Non-pharmacological treatments (therapies and other approaches)

1) Activity pacing and energy conservation (PESE-aware)
Pacing means balancing activity with rest so you avoid post-exertional symptom exacerbation (PESE). Start low, go slow, and increase in tiny steps only when symptoms allow. Global guidance (NICE NG188; World/Long-COVID physio resources) favors pacing and cautions against “pushing through” crashes. NICE+2Home | World Physiotherapy+2

Purpose: Reduce crashes and stabilize daily function.
Mechanism: Avoids repeated over-activation of physiological systems (autonomic, inflammatory, and metabolic) that can worsen symptoms after exertion. Home | World Physiotherapy

2) Graduated, symptom-titrated rehabilitation
A rehab plan that respects PESE can include gentle mobility, breath training, and later strengthening, only when tolerated. Programs should be individualized, avoid rigid step targets, and pause during flares. NICE and WHO-aligned rehab briefings recommend cautious, person-centered progression. NICE+1

Purpose: Restore function safely.
Mechanism: Gradually rebuilds capacity without triggering PESE by matching load to current energy envelope. Home | World Physiotherapy

3) Breathing retraining for dyspnea
Diaphragmatic breathing, slow nasal breathing, and physiotherapy techniques can help dysfunctional breathing and air hunger seen after COVID-19. These strategies are part of multidisciplinary PACS care pathways. NICE

Purpose: Ease breathlessness and anxiety linked to breath control.
Mechanism: Optimizes respiratory mechanics and reduces over-breathing patterns that perpetuate symptoms. NICE

4) Pulmonary rehabilitation (PR) for persistent respiratory symptoms
When breathlessness and deconditioning persist, supervised PR (with careful screening for PESE) can improve breath efficiency and confidence. CDC/NICE endorse structured rehab delivered by trained teams. CDC+1

Purpose: Improve exercise tolerance and quality of life.
Mechanism: Progressive respiratory muscle conditioning and education. NICE

5) Dysautonomia/POTS self-management (fluids, salt, compression)
For orthostatic intolerance or POTS after COVID-19: drink 2–3 L/day fluids, increase salt (often 8–10 g/day if not contraindicated), wear 30–40 mmHg compression stockings/abdominal binders, elevate head of bed, and avoid heat and large carbohydrate loads. Reviews of post-COVID POTS support these first-line measures. Frontiers+2MDPI+2

Purpose: Reduce tachycardia, lightheadedness, and fatigue when upright.
Mechanism: Expands circulating volume and improves venous return to reduce orthostatic heart-rate surge. Frontiers

6) Sleep hygiene and circadian support
Keep a consistent sleep/wake schedule, optimize light exposure, and limit stimulants late in the day. Poor sleep worsens fatigue, pain, and cognition; CDC recommends practical self-care while clinicians treat comorbid insomnia or apnea. CDC

Purpose: Improve restorative sleep and daytime function.
Mechanism: Stabilizes circadian cues and sleep architecture. CDC

7) Cognitive strategies for “brain fog”
Use memory aids, task chunking, and distraction-free work intervals. Clinicians validate symptoms, set realistic goals, and may refer for neuropsychology if available. CDC’s clinical pages emphasize goal-oriented care. CDC

Purpose: Support attention and working memory in daily life.
Mechanism: Compensates for limited cognitive bandwidth and reduces cognitive overexertion. CDC

8) Mental health care (anxiety, depression, PTSD)
Access counseling/CBT, peer support, or psychiatric care as needed. Long COVID can be isolating and disabling; integrated mental health support is recommended by CDC and NICE. CDC+1

Purpose: Reduce distress and improve coping.
Mechanism: Psychotherapeutic tools reduce symptom amplification and improve adherence to pacing/rehab. CDC

9) Nutrition fundamentals
Aim for balanced meals with adequate protein, fiber, and micronutrients; manage post-prandial symptoms with smaller, more frequent meals if dysautonomia is present. Professional bodies advise individualized diet support within Long COVID rehab. publichealth.va.gov

Purpose: Support recovery, muscle preservation, and stable energy.
Mechanism: Ensures substrates for tissue repair and autonomic stability. publichealth.va.gov

10) Return-to-work/school planning and accommodations
Use graded schedules, remote options, and flexible deadlines. Guidance recognizes occupational impacts and the need for adjustments while symptoms fluctuate. NICE

Purpose: Maintain participation without precipitating relapses.
Mechanism: Matches cognitive/physical demands to current capacity. NICE

11) Fatigue management education for patients and families
Teach warning signs of overexertion, flare plans, and supportive communication to prevent inadvertent pressure to overdo. National guidance encourages written self-management plans. NICE

Purpose: Prevent cycles of crash-and-burn.
Mechanism: Reduces PESE triggers through shared understanding. NICE

12) Balance and vestibular therapy (when indicated)
For dizziness or imbalance, targeted vestibular rehab may help if symptoms aren’t driven by PESE. Include safety checks to avoid falls. NICE

Purpose: Reduce dizziness-related disability.
Mechanism: Gradual habituation and gaze stabilization exercises. NICE

13) Head-of-bed elevation and positional strategies
Sleeping with the head elevated and avoiding prolonged standing can reduce morning orthostatic symptoms in POTS. Reviews recommend positional tactics alongside fluids/salt. Frontiers

Purpose: Lessen early-day tachycardia and dizziness.
Mechanism: Diminishes nocturnal diuresis effects and venous pooling. Frontiers

14) Heat management
Avoid hot showers, saunas, and high-heat environments that worsen orthostatic symptoms; consider cooling vests for some. Dysautonomia guides emphasize heat avoidance. American Physical Therapy Association

Purpose: Prevent heat-triggered flares.
Mechanism: Reduces vasodilation and dehydration that aggravate orthostatic intolerance. American Physical Therapy Association

15) Smoking cessation and alcohol moderation
Both can worsen sleep, autonomic symptoms, and inflammation; clinicians routinely counsel reduction. CDC

Purpose: Support systemic recovery.
Mechanism: Lowers inflammatory and autonomic stressors. CDC

16) Vaccination to reduce risk of future COVID-19 episodes
Preventing reinfection may reduce the chance of worsening PACS; CDC promotes vaccination via shared clinical decision-making. CDC

Purpose: Lower risk of new triggers or setbacks.
Mechanism: Reduces severe acute disease and viral burden upon exposure. CDC

17) Symptom diaries and heart-rate monitoring
Simple logs and HR monitors help identify safe activity thresholds and detect early signs of PESE. Care teams use these data to titrate plans. CDC

Purpose: Personalize pacing and rehab.
Mechanism: Biofeedback to avoid overexertion. CDC

18) Social support and peer groups
Peer communities and family support improve adherence and mental health; public-health resources encourage connecting patients to support services. CDC

Purpose: Reduce isolation and stress.
Mechanism: Emotional and practical assistance buffers symptom burden. CDC

19) Structured return-to-exercise only when PESE is absent
If a person has no PESE, a carefully titrated aerobic/strength plan may be considered under clinical supervision; otherwise, prioritize pacing. NICE cautions to tailor activity to symptoms. NICE

Purpose: Rebuild fitness without setbacks.
Mechanism: Progressive overload within symptom limits. NICE

20) Multidisciplinary clinics and referral pathways
Complex cases benefit from coordinated teams (primary care, rehab, mental health, cardiology, pulmonology, neurology). National guidance supports organized services for Long COVID. NICE

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Drug treatments

Important note: The FDA states there are no medicines specifically approved for Long COVID itself. The drugs below are FDA-approved for other conditions and are sometimes used off-label to target particular PACS symptoms. Decisions must be individualized and supervised by a clinician, considering risks, interactions, and contraindications. U.S. Food and Drug Administration+1

1. Duloxetine (SNRI) – neuropathic pain, myalgias, mood
   Dose/Time: Commonly 30–60 mg once daily; timing per clinician advice. Purpose: Reduce neuropathic-type pain and treat co-existing anxiety/depression. Mechanism: Serotonin-norepinephrine reuptake inhibition modulates central pain pathways. Side effects: Nausea, dry mouth, sleep changes, rare liver concerns; avoid with MAOIs. (FDA label for duloxetine/Cymbalta). FDA Access Data

2. Gabapentin (anticonvulsant/neuropathic pain)
   Dose/Time: Often 100–300 mg at night then titrate; adjust in renal disease. Purpose: Neuropathic pain, sleep. Mechanism: Modulates α2δ subunit of voltage-gated calcium channels to reduce excitatory neurotransmission. Side effects: Sedation, dizziness; AED class warning for suicidality. (FDA Neurontin label). FDA Access Data+1

3. Pregabalin (anticonvulsant/neuropathic pain)
   Dose/Time: 50–75 mg at night, titrate; avoid >450 mg/day due to tolerability. Purpose: Neuropathic pain, sleep. Mechanism: α2δ calcium-channel modulation. Side effects: Dizziness, edema, weight gain; AED suicidality warning. (FDA Lyrica/LYRICA CR labels). FDA Access Data+1

4. Amitriptyline (TCA)
   Dose/Time: Low-dose (e.g., 10–25 mg at night) for pain/insomnia. Purpose: Pain modulation and sleep. Mechanism: Serotonin/norepinephrine reuptake inhibition with anticholinergic effects. Side effects: Dry mouth, constipation, QT prolongation risk; use cautiously. (Class information is in standard TCA labels; clinicians consult full FDA labeling for specific products.) NICE

5. Propranolol (beta-blocker) – POTS/orthostatic intolerance
   Dose/Time: Small doses (e.g., 10–20 mg) titrated for symptoms. Purpose: Reduce tachycardia and tremulousness when upright. Mechanism: Non-selective β-blockade blunts heart-rate rise. Side effects: Fatigue, low BP, bronchospasm in asthma. (FDA propranolol labels). FDA Access Data+1

6. Midodrine (alpha-1 agonist) – orthostatic symptoms
   Dose/Time: Commonly 10 mg three times daily (avoid near bedtime). Purpose: Raise standing BP and reduce dizziness. Mechanism: Peripheral vasoconstriction. Side effects: Supine hypertension, scalp tingling; caution in renal disease. (FDA ProAmatine label/NDAs). FDA Access Data+1

7. Fludrocortisone (mineralocorticoid) – volume expansion
   Dose/Time: Low doses per clinician; monitor potassium and BP. Purpose: Expand plasma volume in orthostatic intolerance. Mechanism: Sodium retention. Side effects: Edema, hypokalemia, hypertension. (FDA SPL labeling resource). nctr-crs.fda.gov

8. Droxidopa (prodrug of norepinephrine)
   Dose/Time: Titrated per label for neurogenic orthostatic hypotension; occasionally considered in refractory cases. Purpose: Improve standing tolerance. Mechanism: Raises synaptic NE. Side effects: Headache, hypertension. (FDA Northera label). FDA Access Data

9. Cetirizine (H1 antihistamine)
   Dose/Time: Standard OTC doses; sometimes paired with H2 blockers. Purpose: Manage histamine-mediated symptoms some patients report (rashes, flushing, rhinitis). Mechanism: H1 receptor blockade. Side effects: Drowsiness in some. (FDA Zyrtec/Quzyttir labels). FDA Access Data+1

10. Famotidine (H2 blocker)
    Dose/Time: Per GERD dosing; oral or IV formulations exist. Purpose: Adjunct for histamine-related symptoms; manage reflux that can worsen cough. Mechanism: H2 receptor antagonism reduces gastric acid and histamine signaling. Side effects: Headache; drug interactions via pH-dependent absorption. (FDA famotidine labels). FDA Access Data+1

11. Albuterol (short-acting β2-agonist) inhaler
    Dose/Time: As-needed puffs for bronchospasm. Purpose: Relieve wheeze/chest tightness if reactive airways are present. Mechanism: Bronchodilation. Side effects: Tremor, palpitations. (FDA ProAir/Ventolin labels). FDA Access Data+1

12. Inhaled corticosteroids (e.g., budesonide; fluticasone furoate)
    Dose/Time: Maintenance dosing per label when asthma-like inflammation is diagnosed. Purpose: Reduce airway inflammation. Mechanism: Local glucocorticoid action. Side effects: Oral thrush; rinse mouth after use. (FDA Pulmicort/Arnuity/Breo labels). FDA Access Data+2FDA Access Data+2

13. Low-dose naltrexone (LDN) (investigational for Long COVID)
    Dose/Time: Very low doses used off-label in research settings. Purpose/Mechanism: Hypothesized microglial modulation and anti-inflammatory signaling; RECOVER is evaluating it. Side effects: Vivid dreams, GI upset. (RECOVER trial communications). recovercovid.org+1

14. SSRIs/SNRIs for mood/anxiety (e.g., sertraline, duloxetine)
    Dose/Time: Standard psychiatric dosing under clinician care. Purpose: Treat depression/anxiety that frequently co-occur and worsen quality of life. Mechanism: Monoamine reuptake inhibition. Side effects: Nausea, sexual dysfunction, sleep changes; monitor for interactions. (FDA class labels; duloxetine label cited above). FDA Access Data

15. Melatonin for sleep initiation
    Dose/Time: Bedtime dosing as supplement or Rx where applicable. Purpose: Improve sleep onset. Mechanism: Circadian phase signaling. Safety: Generally well tolerated; discuss with clinician. (Clinical practice guidance references self-care within CDC resources). CDC

16. Modafinil (wake-promoting agent)
    Dose/Time: Off-label, carefully selected cases of severe hypersomnolence; avoid if PESE dominates. Purpose: Improve daytime alertness. Mechanism: Promotes wakefulness via dopaminergic pathways. Side effects: Headache, anxiety, insomnia; interactions caution. (FDA Provigil labeling informs risks; off-label for Long COVID). NICE

17. Acetaminophen/NSAIDs for pain and headaches
    Dose/Time: As labeled, respecting maximum daily doses and GI/renal cautions. Purpose: Symptomatic pain relief. Mechanism: COX inhibition (NSAIDs) and central actions (acetaminophen). Side effects: GI, renal, hepatic risks based on product. (FDA consumer safety communications). U.S. Food and Drug Administration

18. Intranasal corticosteroids for chronic rhinitis
    Dose/Time: Daily sprays per label. Purpose: Treat nasal inflammation, smell-loss-related rhinitis. Mechanism: Local anti-inflammatory action. Side effects: Nasal irritation/bleed. (FDA fluticasone furoate nasal label). FDA Access Data

19. Baclofen or tizanidine (for spasm where appropriate)
    Dose/Time: Low-dose titration by clinician for painful spasm. Purpose: Reduce muscle tightness that worsens fatigue/pain. Mechanism: CNS muscle-relaxant pathways. Side effects: Sedation, hypotension; avoid if falls risk is high. (Refer to FDA product labels for chosen agent). NICE

20. Topical agents for neuropathic pain (lidocaine/capsaicin patches)
    Dose/Time: Per label. Purpose: Local pain control with fewer systemic effects. Mechanism: Peripheral sodium-channel blockade or TRPV1 desensitization. Side effects: Local irritation. (FDA product labels). NICE

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Dietary molecular supplements

There is no supplement proven to cure Long COVID. Some small studies and prior evidence from related conditions suggest possible benefit for select symptoms. Quality varies; use reputable products and check for drug–supplement interactions.

1. Coenzyme Q10 (CoQ10)
   CoQ10 supports mitochondrial energy generation and acts as an antioxidant. A small RCT combining CoQ10 with alpha-lipoic acid improved symptom scores in “chronic COVID syndrome,” though the evidence base is still limited. Typical doses in studies range 100–200 mg/day. Function/Mechanism: Electron transport chain cofactor and antioxidant; may support cellular energy. PubMed Central

2. Alpha-lipoic acid (ALA)
   ALA is a mitochondrial cofactor with antioxidant activity; it has been used with CoQ10 in a small trial for chronic COVID symptoms. Typical supplemental doses are 300–600 mg/day. Function/Mechanism: Redox cycling and mitochondrial enzyme cofactor; may reduce oxidative stress. PubMed Central

3. Acetyl-L-carnitine (ALCAR)
   ALCAR shuttles fatty acids into mitochondria. It is sometimes paired with ALA/CoQ10 based on pre-existing fatigue research. Doses often 500–1000 mg 1–2×/day. Function/Mechanism: Supports mitochondrial beta-oxidation and energy generation. ScienceDirect+1

4. Vitamin D
   Observational studies link low vitamin D with higher risk and severity of persistent symptoms; supplementation corrects deficiency but has not yet proven to cure Long COVID. Dosing depends on baseline level and local guidelines. Function/Mechanism: Immunomodulation and musculoskeletal health. PubMed Central+1

5. Omega-3 fatty acids (EPA/DHA)
   Pilot RCTs and feasibility studies explore omega-3s for Long COVID and broader COVID recovery, with mixed but biologically plausible results. Typical doses range 1–2 g/day EPA+DHA. Function/Mechanism: Anti-inflammatory lipid mediators (SPMs). PubMed Central+1

6. Magnesium
   Common cofactor in energy and nerve function; may help sleep and muscle symptoms in some patients. Dose varies (e.g., 200–400 mg elemental/day), balanced against GI tolerance. Function/Mechanism: ATP metabolism and neuromuscular stability. NICE

7. N-acetylcysteine (NAC)
   Precursor to glutathione; studied in other oxidative stress conditions and sometimes used empirically in PACS. Typical doses 600–1200 mg/day (drug interactions and GI side effects considered). Function/Mechanism: Antioxidant replenishment. SpringerLink

8. B-complex vitamins
   Support mitochondrial enzymes and nerve health; correct documented deficiencies first. Function/Mechanism: Cofactors in energy metabolism and neurotransmitter synthesis. NICE

9. CoQ10 + ALA combination
   Some clinicians combine these based on the small RCT signal and mitochondrial hypothesis; dosing follows individual components. Function/Mechanism: Synergistic mitochondrial and antioxidant effects. PubMed Central

10. Curcumin (with enhanced bioavailability)
    Investigated for anti-inflammatory effects in other conditions; quality and interactions vary. Function/Mechanism: NF-κB and cytokine modulation (preclinical/adjacent evidence). SpringerLink

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Immunity-booster / regenerative / stem-cell drugs

There are no FDA-approved stem-cell or “regenerative” drugs for Long COVID. The FDA repeatedly warns consumers to avoid clinics selling unapproved stem-cell or exosome products for COVID-related conditions because they can be unsafe and illegal. Participation in regulated clinical trials (e.g., NIH RECOVER) is the safe path for experimental therapies. recovercovid.org+3U.S. Food and Drug Administration+3U.S. Food and Drug Administration+3

Because no such drugs are approved for PACS, clinicians sometimes optimize evidence-based vaccines, nutrition, sleep, exercise pacing, and control of comorbidities to support immune health, rather than prescribing unproven “immune boosters.” This conservative approach aligns with FDA and public-health guidance prioritizing safety and trial participation. CDC+1

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Surgeries

Surgery is not a treatment for PACS itself. Operations are reserved for separate, specific diagnoses (for example, sinus surgery for chronic structural sinus disease, or cardiac/pulmonary procedures for unrelated structural problems) after standard evaluation. Long COVID care focuses on non-surgical symptom control and rehabilitation unless a distinct, surgically correctable condition is identified. This approach matches national guidance that PACS is managed supportively and symptom-specifically. NICE+1

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Preventions

1. Avoid reinfection (vaccination, masks in high-risk settings, ventilation). CDC

2. Early testing and guideline-based acute COVID care if infected. U.S. Food and Drug Administration

3. Rest adequately during acute illness; don’t rush back to intense activity. CDC

4. Manage chronic conditions (BP, diabetes, asthma) to reduce setbacks. CDC

5. Sleep hygiene and regular routines to support recovery. CDC

6. Balanced diet with enough protein, fiber, and micronutrients. publichealth.va.gov

7. Gradual, symptom-led activity instead of “push through the crash.” Home | World Physiotherapy

8. Heat management and hydration in dysautonomia. American Physical Therapy Association

9. Alcohol moderation and no smoking. CDC

10. Seek care in multidisciplinary services when symptoms persist. NICE

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When to see a doctor

See a clinician if symptoms last beyond a month, limit daily life, or worsen with activity; urgently seek care for chest pain, severe shortness of breath, signs of blood clots, syncope, or new neurologic deficits. Clinicians should rule out alternative causes, document orthostatic vitals if dizziness/tachycardia occur, and build a symptom-focused care plan (CDC/NICE). CDC+1

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What to eat (and what to avoid)

1. Prioritize protein at each meal to preserve muscle. publichealth.va.gov

2. Colorful plants and fiber for micronutrients and gut health. publichealth.va.gov

3. Hydration: 2–3 L/day water unless contraindicated; add salt if advised for POTS. Frontiers

4. Small, frequent meals if large meals worsen dizziness or fatigue. American Physical Therapy Association

5. Omega-3–rich foods (oily fish, flax, walnuts) as anti-inflammatory support. PubMed Central

6. Correct deficiencies (e.g., vitamin D) under medical guidance. PubMed Central

7. Limit ultra-processed, very sugary foods that can trigger post-prandial dips. American Physical Therapy Association

8. Moderate alcohol and caffeine, which can worsen sleep and dysautonomia. American Physical Therapy Association

9. Consider dietitian referral for under-nutrition or complex needs. NICE

10. Be cautious with supplements; choose reputable products and confirm interactions. CDC

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Frequently Asked Questions (FAQs)

1) Is Long COVID real even if my tests are normal?
Yes. Major health agencies recognize PACS. Symptoms and function—not just test results—guide care. CDC+1

2) Is there a cure or FDA-approved medicine for Long COVID?
Not yet. Treatments target symptoms while large trials (e.g., RECOVER) test options. U.S. Food and Drug Administration+1

3) Should I try to “push through” fatigue?
No. Pacing and energy conservation reduce post-exertional crashes; overexertion can set recovery back. Home | World Physiotherapy

4) Can rehab help if I have PESE?
Yes—but it must be gentle and symptom-titrated, not a fixed, graded schedule. NICE

5) What if I have dizziness and fast heartbeat when standing?
You may have orthostatic intolerance or POTS; increase fluids/salt (if safe), wear compression, and see a clinician to consider medications. Frontiers

6) Do antihistamines help?
Some people report relief of certain symptoms; H1/H2 blockers are used for allergies/reflux and sometimes tried off-label. Discuss risks and interactions. FDA Access Data+1

7) Should I get vaccinated after Long COVID?
Vaccination decisions use shared clinical decision-making; preventing reinfection is a reasonable goal. CDC

8) Are stem-cell or “regenerative” clinics a solution?
No—unapproved stem-cell products marketed for Long COVID are unsafe/illegal according to FDA. Avoid them outside regulated trials. U.S. Food and Drug Administration

9) Will omega-3s, vitamin D, or mitochondrial supplements cure me?
No supplement cures Long COVID, but correcting deficiencies and select trials (e.g., CoQ10+ALA) suggest possible symptom benefit for some. Evidence remains preliminary. PubMed Central+1

10) Why does my heart race with mild activity?
Autonomic nervous system changes after infection can cause orthostatic intolerance; first-line care is non-pharmacologic with meds reserved for select cases. Frontiers

11) Can inhalers help persistent cough/wheeze?
If you have airway hyperreactivity, clinicians may use bronchodilators and inhaled steroids per asthma guidelines. FDA Access Data+1

12) How long does recovery take?
It varies widely. Some people improve over months; others need longer support. Pacing and symptom-led care are key. CDC

13) What records should I keep?
Symptom, activity, HR, sleep, and flare triggers to guide personalized plans. CDC

14) Where can I find trustworthy information?
WHO, CDC, NICE, and NIH RECOVER hubs provide updated, evidence-based resources. recovercovid.org+3World Health Organization+3CDC+3

15) What’s the single most important safety point?
If symptoms are severe or rapidly worsening—especially chest pain, breathlessness, syncope, or new neurologic signs—seek urgent care to rule out other conditions. CDC

Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical  history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.

The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members

Last Updated: November 09, 2025.

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