Possible Causes
There are currently no clear theories or test methodologies regarding the cause of the Post-Covid-Syndrome.
However, we do already know which typical problems and symptoms Post-Covid-Patients usually face. Furthermore, there is a variety of research looking at the different "puzzle pieces" that have typically developed in Post-Covid patients.
Especially in patients who have been suffering from Post-Covid for several months, it is likely that one root cause has developed into several problem areas, each of which contribute to the symptoms:
At the moment, there are only theories and no tests for many of these puzzle pieces.
Nevertheless, by closely observing your symptoms, you can certainly narrow down which areas might be the most relevant for you. (You can then use the page Treatments to find approaches fitting for you.)
Solving individual problems or "puzzle pieces" often brings some improvement. However, in order to recover completely, it is likely that each of the individual problem areas needs to be resolved.
The following is an overview of the most popular theories regarding possible causes of Post-Covid, possible affected areas and possible puzzle pieces.
In no way do I want to imply a ranking or causality between the various puzzle pieces.
"What came first" is simply not yet clear. Some of the pieces of the puzzle are certainly closer to the "root cause", and some closer to the "symptoms", but this might be individually different for each person.
Viral Residues and Reactivations
Are remaining parts of the Covid-19 virus hidden somewhere in the body, permanently provoking the immune system?
Or did the Covid-19 infection reativate other latent viruses, e.g. EBV or CMV? As a result, patients with the Post-Covid-Syndrome might have been struggling with an active infection for months.
It is also possible that Covid-19 has weakened the immune system to such an extent that bacteria or parasites have been able to spread in the body and are now causing the symptoms.
Diagnosis:
Test for reactivated viruses, bacteria, parasites. MD & specialist laboratories. Recommended tests listed on page Diagnosis.
Treatment:
Depending on the pathogen, treatment is antiviral or antibacterial. See page Medication.
Inflammation
It is well known that the body fights active viruses with inflammation.
However, it could be that these inflammations have caused damage to organs (inflammation of the heart, liver, adrenal glands, etc.), which persists even after the infection.
It is also possible that the immune system "overreacts" permanently in Post-Covid patients (possibly triggered by existing virus residues in the body) and constantly creates new inflammations. These inflammations could: Continue to attack organs, weaken the blood vessels and circulation, keep the body in "permanent defense mode".
Diagnosis:
Test for inflammatory markers and Post-Covid biomarkers. MD. Recommended tests see page Diagnosis.
Treatment:
E.g. with Cortisone, Monoclonal antibodies. See Medication.
Autoantibodies
As a result of the immune system's "overreaction", Post-Covid patients seem to often form so-called autoantibodies.
These often attack one's own body, and are directed e.g. against blood vessels, heart cells, lungs or brain cells.
Diagnosis:
Special laboratories, e.g. "Cellttrend".
Treatment:
Immunoadsorption (controversial).
Neuroinflammation
The inflammatory reactions described above may also have spread to the brain.
The brain stem and vagus nerve in particular appear to be affected in Post-Covid patients.
These areas are responsible for autonomic functions such as breathing and heartbeat, which would explain some of the typical Post-Covid symptoms.
Microclots & Impaired Oxygen Supply
Many new studies on PCS are investigating the possibility that so-called "microclots" remain permanently in the body after a Covid-19 infection and disrupt the supply of oxygen to the organs.
These microclots can usually only be detected using special microscopy equipment, but not with standard blood tests at the GP.
Diagnosis:
Dark-field microscopy (e.g. Dr. Jäger in Bad Aibling, Clinicum St. Georg, Germany)
Treatment:
E.g. Blood thinners, H.E.L.P. apheresis, Ozone therapy, HBOT
Vascular Deficiency
Along with inflammation, reduced oxygen supply and microclots, severe damage to the inner walls of the blood vessels (endothelia) has been observed in Post-Covid patients.
In fact, this is so characteristic of the Post-Covid-Syndrome that some Post-Covid clinics use a special eye examination measuring the strength of the vessels, and recognize reduced strength as a biomarker/evidence of PCS.
Diagnosis:
OCT-A eye examination, offered by some Long Covid clinics.
Treatment:
E.g. Cryotherapy, Wim-Hof method, Pycnogenol.
Muscles and Lactate
New studies show that even if the oxygen supply in the blood itself is sufficient, the muscles of many PCS patients cannot absorb enough oxygen from the blood.
In addition, the lactate levels in the muscles are often too high even at rest, which would explain muscle fatigue and weakness.
Diagnosis:
Blood gas analysis. General practitioner or pulmonologist.
Treatment:
E.g. N-acetylcysteine (NAC)
Mitochondriopathy
Mitochondria are the power plants of our cells. They need oxygen and glucose to supply our body with energy.
It seems possible that the mitochondria were attacked during the Covid-19 infection, or that they are not supplied with enough oxygen due to vascular damage or microclots in the blood.
As a result, the mitochondria become weaker and weaker, resulting in exhaustion and fatigue.
Diagnosis:
Test for nutrients within the mitochondria. General practitioner & specialist laboratories.
Treatment:
E.g. IHHT, Ozone therapy, HBOT.
Gut Microbiome
The gut is often referred to as the center of the immune system.
Here, a fine balance of different beneficial bacteria is required.
During the Covid-19 infection, this bacterial balance might have been disrupted, especially if the patients used antibiotics.
As a result, the immune system is weakened.
Diagnosis:
Test stool sample for bacterial composition.
Treatment:
Probiotics, Gut detox.
Biofilms
Normally, our body is able to fight off viruses and bacteria within a short time.
Under certain circumstances, however, it is possible that so-called "biofilms" form in the body. These biofilms consist of particularly stubborn bacteria.
Biofilms are found, for example, in the mucosa of the throat, nose, ears and eyes.
It is conceivable that such biofilms contribute to the constant irritation of the immune system and the body.
Mast Cell Activation Syndrome
Mast cells are an integral part of the immune system. It has been proven in the past, especially in patients with allergies, that mast cells can "overreact" and thus cause allergies.
Many PCS patients also appear to suffer from an overreaction of the mast cells, in the form of the so-called Mast Cell Activation Syndrome (MCAS).
Diagnosis:
Test for specific biomarkers. MCAS specialists & special laboratoryies.
Treatment:
E.g. Antihistamines. More info here.
Hormone Deficiency
The Covid-19 infection also appears to attack the human hormone system. If one or more hormones is not sufficiently produced anymore, this would explain symptoms such as fatigue. The hormones Cortisol, ACTH, Serotonin, and Adrenaline are particularly often affected.
Diagnosis:
Endocrinologist.
Treatment:
Hormone replacement.
Sympathetic / Parasympathetic Nervous System
A theory sitting between established medicine and naturopathy. Under normal circumstances, the autonomic nervous system (ANS) regulates two states: The sympathetic nervous system (stress), and the parasympathetic nervous system (rest, relaxation).
PCS patients, in conjunction with an impairment of the vagus nerve, often suffer from an overactivation of the sympathetic nervous system, which keeps the body in a state of "permanent stress" and prevents it from regenerating properly.
Diagnosis:
Osteopath.
Treatment:
E.g. Vagus nerve stimulation, Meditation.
Dysautonomia
The term dysautonomia is used when bodily functions that should normally run unconsciously and automatically suddenly exhibit unusual behavior. This includes the regulation of breathing, heartbeat and body temperature.
Diagnosis:
Observation
Treatment:
Depending on the area affected, e.g. Ivabradine, Respiratory therapy.
Vitamin Deficiency
Post-Covid patients are often lacking proper amounts of vitamins, minerals or amino acids. This could explain why the body and immune system cannot function optimally.
Sleep
Studies show that up to 83% of Post-Covid patients also suffer from sleep disorders.
This is certainly related to the issues of neuroinflammation, sympathetic nervous system, and dysautonomia, as already described.
If one's sleep is disturbed, the body cannot fully regenerate, and symptoms might become progressively worse.
Diagnosis:
Sleep laboratories.
Treatment:
Depending on the type of sleep disorder, e.g. CPAP, BiPAP. Supporting tools: Weighted blanket, Snoring splint, Snoring vest.