Symptoms persisting months after infection have investigable mechanisms.
The World Health Organization defines Long COVID as the persistence or emergence of symptoms three months after infection, lasting at least two months, with no other diagnostic explanation.
What it is
The condition comprises manifestations that continue after the acute infection resolves. The scientific literature is actively investigating its mechanisms, among them immune dysfunction with persistent inflammation, autonomic dysregulation, mast cell activation and changes in tissue perfusion. Routine laboratory markers are frequently unremarkable.
Long COVID
This list is informational and is not a self-diagnosis instrument. Isolated signs do not characterize the condition. Medical assessment considers the whole picture, its evolution and the applicable diagnostic criteria.
Systemic
- Disproportionate, persistent fatigue
- Malaise after physical or mental exertion
- Exercise intolerance
Cognitive
- Difficulty concentrating
- Working memory lapses
- Slowed processing
Cardiovascular
- Palpitations
- Dizziness on standing
- Heart rate variation
Respiratory
- Exertional breathlessness
- Sensation of incomplete breathing
Sleep and sensory
- Non-restorative sleep
- Persistent changes in smell and taste
- Reactions that did not exist before infection
Situations that warrant investigation
Symptoms sustained for three months or more after infection
Consistent worsening after exertion, delayed by hours or days
Unremarkable routine tests despite meaningful functional limitation
Emergence of orthostatic intolerance or allergy-like symptoms after infection
What the literature investigates
The described mechanisms may coexist in the same patient. Integrated assessment is what allows identification of which are present.
Low-grade inflammation maintained after resolution of the acute illness.
Altered autonomic control, frequently with repercussions on heart rate and tolerance of the upright position.
Release of inflammatory mediators with allergy-like manifestations emerging after infection.
Changes in tissue perfusion under study as part of the explanation for fatigue and cognitive changes.
How the investigation is conducted.
A defined path, with stages that build on one another. Each consultation begins where the previous one ended.
Listening and clinical timeline
Reconstructing the trajectory: when each symptom appeared, what preceded it, how it evolved and what has already been investigated. The order of events often points to the mechanism.
Integrating symptoms and systems
Joint analysis of skin, digestive tract, cardiovascular system, sleep and cognition. Symptoms treated as separate fragments rarely reveal what they share.
Hypotheses and targeted testing
Tests chosen from defined hypotheses, with attention to the correct moment of collection. In some conditions, the result depends on when the sample is taken.
Plan, follow-up and referrals
Reasoned direction, with follow-up of the response and, when the presentation calls for another specialty, the appropriate referral.
Criteria and limitations
The definition is clinical. There is, at present, no single test that confirms or excludes the condition.
Mechanisms remain under active investigation and conduct follows the evolution of the literature.
Post-exertional malaise, when present, modifies conduct and contraindicates intensive progressive exercise approaches.
Request information about the consultation
Briefly describe your case. The team will get in touch with guidance on the investigation and scheduling options.
This form does not perform clinical triage, does not establish a diagnosis and does not replace a medical consultation. Information is used solely for contact and scheduling guidance, under Brazilian data protection law (LGPD).
Frequently asked questions
Is Long COVID psychological in origin?
No. The condition is recognized by the World Health Organization and has a pathophysiological basis under active investigation: immune dysfunction, persistent inflammation, autonomic dysregulation and microvascular changes are among the mechanisms studied.
How long does the condition last?
The course varies considerably between patients. Identifying the specific mechanisms present in a given case — such as autonomic dysregulation, mast cell activation or a sleep disorder — guides conduct and may influence the trajectory.
What is post-exertional malaise?
Worsening of symptoms after physical or mental activity, frequently delayed by hours or a day. It is a relevant element of assessment because it directly alters conduct.
What should I record before the consultation?
The date of infection and when each symptom appeared, what aggravates and relieves them, sleep and energy patterns across the day and, if possible, heart rate lying down and after 2, 5 and 10 minutes standing.
Conditions investigated.
Mast Cell Activation Syndrome
Reactions involving skin, digestive tract, cardiovascular and nervous systems at once, without allergy testing explaining the picture.
Ehlers-Danlos Syndrome
Connective tissue alterations with joint, cutaneous and systemic repercussions, assessed against current international criteria.
Sleep Medicine
Assessment of sleep architecture and quality as a structural axis, frequently the element that reorganizes the understanding of a complex case.