Does Long COVID cause Postural Orthostatic Tachycardia Syndrome? An analysis

Long COVID is the persistence of symptoms and conditions associated with COVID for more than four weeks after the initial infection. It's used as an umbrella term for various symptoms and conditions that can occur all over the body, which makes it pretty different from traditional illnesses.

Although today it's widely recognized and accepted by the medical community, the term Long COVID was actually coined by patients first. Since it's not just one condition, you'll likely hear it referred to in medical news and literature as Post-Covid Conditions or PCC.

What are the symptoms of Long COVID?

Many of the symptoms associated with Long COVID are easily identifiable because they're the same ones you would have had with COVID. What makes Long COVID different is that symptoms persist weeks to months longer than the normal 1-14 day timeframe. These symptoms can also be accompanied by novel ones or others that come and go, change, or worsen over time. The most common symptoms of long COVID are:

• Prolonged daily fatigue
• Issues with sleep, insomnia that results in daytime fatigue
• Restless legs syndrome (especially at night)
• Brain fog
• Dizziness and headaches
• Fever and chills
• Weakness
• Distorted or lost sense of smell or taste
• Cough, shortness of breath
• Rapid or irregular heartbeat

Is Long COVID an autoimmune disease?

Although the research is ongoing, Long COVID itself is not considered an autoimmune disease. There is evidence, however, that SARS-CoV-2 can trigger or uncover other autoimmune disorders. An autoimmune disease is a condition in which your immune system malfunctions and attacks its healthy cells. Patients with autoimmune disorders have "autoantibodies" circulating in their bodies, which are antibodies designed to attack their own cells. Interestingly, one 2023 study showed that Long COVID patients tend to have elevated levels of autoantibodies for up to 12 months after infection.

There are a handful of viruses and pathways that are known to provoke autoimmune disorders, like Epstein-Barr Virus (EBV) triggering Lupus, or rubella virus triggering rheumatoid arthritis (RA), so SARS-CoV-2 shouldn't be considered an exception without ample evidence. For now, though, it may be safer to say that Long COVID appears to be "autoimmune-related" and that the topic deserves more research.

As you can tell by the incredible range of symptoms brought on by Long COVID, narrowing down its causes and effects is no simple task. There are several mechanisms that Long COVID uses to manifest itself in patients. For example, sometimes the virus sticks around longer than normal and causes low-level inflammation. In other cases, the virus triggers new autoimmune conditions or re-activates dormant infections.

Since we're discussing how Long COVID affects the human body, it's important to understand that tons of conditions tend to have overlapping symptoms. This can make it tricky to differentiate between causation and correlation – in other words, one thing that directly causes something else is different from two things that occur at the same time without necessarily being related. This difference has a massive impact on understanding what exactly is causing symptoms and how to go about treatment.

Some of the diseases and symptoms that overlap with Long COVID can be seen in the above graphic, organized by body system.

Although research has been able to identify these symptoms and pathologies, it remains largely unclear why each tends to co-occur with Long COVID. Because there are so many potential routes Long COVID can take in affecting patients, each symptom requires its own mechanistic research.

In a 2022 observational study of post-COVID patients, researchers found that patients were at the highest risk for being newly diagnosed with diabetes, hypertension, and POTS. Although each of these diseases is well-known in the medical world, POTS can be easily overlooked despite its massive effect on patient well-being.

POTS, or Postural Orthostatic Tachycardia Syndrome is a disorder where your heart consistently beats too fast after standing or sitting upright. It can cause symptoms like fatigue, lightheadedness, nausea, and shortness of breath. For reasons that aren't completely understood, it mostly affects women from the ages of 15 to 50 years old and like Long COVID, happens for lots of reasons.

POTS is one of the conditions that falls under the umbrella of Dysautonomia, which is a more general term for autonomic nervous system dysfunction. The autonomic nervous system controls bodily processes that occur unconsciously, like your heart beating, breathing, or digestion.

When you've been sitting or lying down for a while, blood becomes spread out throughout your body. So, when you stand or sit up, non-POTS patients' bodies normally push blood back up into the brain and upper half of the body. There are several steps involved in pushing blood toward the brain, but this process is mostly dependent on autonomic nerve signals that increase heart rate and constrict blood vessels to fight gravity's downward pull.

For POTS patients, their bodies have a harder time adjusting blood flow to the brain, which is why they often experience light-headedness, fatigue, and brain fog.

Their heart rate speeds up because of a lapse in communication between hormones meant to increase blood pressure and the tissues that do the work to move the blood. This lapse in communication can happen anywhere along the signaling pathway, meaning it can be due to things like nerve damage or blood vessel dysfunction. In some patients though, there's no issue with this signaling pathway, and they instead have overall low blood volume.

Alongside the increasing number of Long COVID patients, there's an increasing amount of patients with post-COVID POTS. One study from 2022 found that 66% of their pool of female patients with Long COVID also reported symptoms of dysautonomia (the disease group to which POTS belongs). It's important to consider this number in its context though, since females are at a much higher risk of having POTS in the first place.

Based on the literature from 2023, the current understanding is that the COVID-19 virus may trigger several problems:

1. Autoimmunity: The SARS-CoV-2 virus can cause your immune system to make antibodies against its own body's cells, these are known as "autoantibodies". Some of these antibodies disrupt hormones that are meant for blood vessel constriction, making them worse at their job and causing POTS in some patients.
2. Direct Damage: The spike protein in the COVID-19 virus can directly damage tissues in many systems. When this protein damages the right nerves, it can end up inducing POTS.
3. Neuroinvasion: COVID can invade the autonomic nervous system (ANS), including the brainstem. When this control tower is disrupted, it can also induce POTS.
4. System Overload: The body's reaction to the virus, including the fever and the immune response (a flood of chemicals called cytokines), can overload the Autonomic Nervous System, making it go into overdrive and function less effectively.

All of these effects can lead to the symptoms of POTS. Think of it as a series of malfunctions at every level—from individual nerve signals to the whole nervous system—that results in the chaotic flow of communication within the rest of your body's systems. Researchers are still putting the pieces together, but it's clear that COVID-19 can leave a lasting impact on the body's complex internal signaling system.

POTS and Long COVID management

If you're navigating POTS as a part of your Long COVID recovery, there are several practical steps you can take.

• Make sure you're drinking plenty of fluids and getting enough salt, as this can help maintain your blood volume.
• Compression socks and gloves are a great help in keeping your circulation on track.
• When getting up from lying down, do it gradually to prevent dizziness.
• Your doctor might also suggest certain medications to help regulate your heart rate and blood pressure.
• Never underestimate the power of good rest and taking it easy when you need to.

This story was produced by Guava Health and reviewed and distributed by Stacker Media.