Dr. Maigaelle Moulene Long Covid
Resource

UNDERSTANDING LONG COVID: PHYSIOLOGICAL CAUSES

​

One of the biggest obstacles LC patients face is the lack of diagnostic tests and understanding in the community about the impact Long Covid can have on patients. Doctors, without formal diagnostic tools and treatment protocols, have no idea what to do with these patients. Long Covid was not taught in medical school, there is little formal research on it, and professional education to doctors is flimsy at btest. Most doctors are specialists; they do not know anything about Long Covid. I hear time and time again that Long Covid patients have to be their own doctors and advocates. This resource highlights the patho-physiological mechanisms of covid: this is what covid actually does to the body and the current research out there.

 

Understanding the patho-physiology is the first step in understanding how to treat Long Covid. The effects of covid is multifactorial: the symptoms are not caused by just one cause. Different symptoms are caused by different effects, therefore, the symptoms must be treated individually. (1)

​​​

1. Ongoing inflammation/hyperinflammation 

Everyone knows that Covid causes inflammation: everyone has heard about the 'cytokine storm,' which basically means that all these cells that cause inflammation are released and cause damage to every organ in your body. The inflammation is thought to be due to many different factors, including dysfunction of the immune system, which causes damage to every organ. Inflammation is known to cause everything from appendicitis to pancreatitis and diabetes and cardiovascular disease. (1) 

​

Symptoms: Pain, brain fog, insomnia, fatigue, rashes, abdominal pain etc.. 

​​​​

2. Gastrointestinal Effects: Gut permeability (Leaky Gut) and Microbiome alteration

The gut has been shown to play a central role in Long Covid, with the covid virus increasing gut permeability, decreasing absorption of tryptophan and therefore the production of serotonin, being a reservoir for viruses, and altering the microbiome and immune regulation. (4).​​ Covid has been found to alter the microbiome of the gut, leading to many gastrointestinal symptoms and is also involved in immune regulation.

​

The authors of one of the studies postulated microfloral dysbiosis contributes to symptoms via increased gut inflammation, impaired gut wall integrity which correspondingly leads to systemic inflammatory dysfunction, reduced immune surveillance leading to greater nongut symptoms as well [4-6,8,11,12]. In this situation, overgrowth of less favourable gut bacteria have been found in the systemic circulation and within pulmonary aspirates leading to an increased inflammatory response, causing cough and breathlessness (20)

 

70% of the immune cells are located in the gut and therefore the gut is now known to be involved in immune regulation (1,4). This immune response causes inflammation all over the body.

 

Also, biopsies of the gastrointestinal system have shown that virus remnants still persist in the gut long after the acute infection has passed. (1) These cause ongoing inflammation in the body. 

​​

Symptoms: abdominal pain, reflux, gas, bloating, diarrhea. 

​​​​

3. Immune System Disorders and Dysfunction 

Studies have shown that covid causes alterations in immune cells which causes changes in immunity and hyperinflammation (1). There is evidence of chronic inflammation and ongoing immune response which causes tissue damage and chronic symptoms (4). 

Several studies have shown increased levels of autoantibodies which is your own cells attacking its own body and can affect every organ in the body. (1) Reactivated viruses like EBV viruses have also been determined to have an impact on Long Covid. (1)

​​​

Symptoms: increased infections; cellulitis, urine infections, throat infections, EBV re-activation.

​​

​​4. Neurological/Nervous System Changes: Autonomic Nervous System Dysfunction 

The autonomic system controls all the involuntary functions of our body like heart rate, blood pressure, and digestion and is a significant factor in Long Covid. Many patients are being diagnosed with dysautonomia, which is a dysfunction of the autonomic nervous system and the body being stuck in a 'fight or flight' response (4). 

​​​

Symptoms: tachycardia, dizziness, fatigue, gastrointestinal issues and other symptoms (4). 

​​

5. Circulatory System Damage: Damage to blood vessel walls and increased clotting

Damage and inflammation to the circulatory system from covid has been established, leading to increased risks of clots, impaired blood flow and bleeding. Microclots, small blood clots, have been found both in acute and long covid (1,4). Months after acute covid, patients have had large blood clots like embolisms and strokes and deep vein thrombosis as well as bleeding events (1). Blood cells are also thought to be affected, causing shortness of breath, fatigue, 'brain fog' (cognitive dysfunction), muscle pain from decreased blood flow and and tissue damage (4). Platelets, which are involved in blood clotting, are also thought to be affected. 
 

Symptoms: Shortness of breath, brain fog, post-exertional malaise, fatigue. 

​​​​​

6. Nerve Damage: Dysfunction of the Vagus Nerve 

The Vagus Nerve is the main link between the brain and the rest of the body to control the 'rest and digest' part of our bodily functions, the autonomic dysfunction. It links the brain stem to the heart, the digestive system, the immune system, mood, skin and muscle sensation and speech/taste. Covid has been found to cause Vagus Nerve inflammation, irritation and therefore autonomic dysfunction. It can cause neck and shoulder pain, headaches and migraines, acid reflux, increased heart rate and hoarseness of the voice. It also innervates the stomach and causes gastroparesis, abdominal pain, bloating, and acid reflux. The Vagus Nerve is also responsible for immune response activation and regulates inflammation. With an inflamed vagus nerve, inflammation is never turned off (2). It causes dysautonomia and autonomic nervous system fatigue: heart rate variability, increased sympathetic drive, depletion of energy stories, chronic fatigue, decreased oxygen, and increased body temperature. 

​​​

Symptoms: Neck and shoulder pain, bloating, gastroparesis, increased heart rate, headaches and migraines, chronic fatigue, acid relux, abdomminal pain, hoarseness of voice, increased inflammation. 

​​​

7. Decreased Serotonin

90% of serotonin is produced in the gastrointestinal wall and covid seems to decrease the absorption of tryptophan, its precursor, as well as decrease its storage and enhances its turnover. This decreased serotonin affects mood, memory, cognition, and overall mental health. It also affects gut motility and the control of digestion. (3,4)  

​​​​

Symptoms: low mood, decreased memory, decreased cognition. 

​​​​​​

8. Mast Cell Activation Syndrome

Long Covid patients have an increased number of allergic reactions due to an increased release of histamine. Most of mast cells are found in the gut. This increased histamine causes hyperinflammation. (5)​

​

Symptoms: skin rashes, allergic reactions to foods/allergens. 

​​​​

9. Mitochondrial Damage causing energy depletion 

The mitochondria are the powerhouse of cells, responsible for producing energy in cells. In Long Covid patients, 60% have mitochondrial changes and many don't work as well therefore produce less energy. This mitochondrial dysfunction causes decreased energy, cardiovascular abnormalities, shortness of breath, cognitive dysfunction, and chronic fatigue (6).​​

​​

Symptoms: chronic fatigue, shortness of breath, brain fog, post exertional malaise.

​​

10. Persistent Viruses 

Pockets of viruses have been found in the gastrointestinal system, which is thought to be one of the causes of ongoing inflammation.

​

11. Hormonal Changes 

People with Long Covid were found to have much lower levels of cortisol levels than those without. Other hormonal imbalances in women were also found including increased menopausal 

​​​​

​​​​

​​​​​​​​​