COVID-19 is over, so why am I still short of breath and tired? | Long COVID

1. The Illness Has Ended, But Why Has My Body Not Recovered?

People say COVID-19 is over. Masks are off, and the number of confirmed cases no longer makes headlines. But... aren't you hearing more often these days about unusual fatigue, shortness of breath, and heart palpitations even after minor activity?

Many patients visiting our clinic complain, "Tests show nothing wrong, but I get short of breath and struggle just climbing stairs," or "Before, I was fine even after a day of overtime, but now I'm drained by lunchtime." But is this simply something we can attribute to age or lack of exercise?

2. Shortness of Breath and Fatigue: Seemingly Similar, Yet Distinct

Shortness of breath literally means that oxygen supply cannot meet demand. Respiration is rapid, but oxygen isn't getting in—indicating a bottleneck in the supply system somewhere in the lungs, heart, or circulation. Fatigue, on the other hand, occurs when the energy system that utilizes oxygen or nutrients malfunctions, even if they reach their target. This could signal a breakdown in more complex and fundamental recovery systems, such as muscle metabolism, intracellular resilience, mitochondrial function, or nervous system integration.

These two symptoms intertwine, creating a vicious cycle. Shortness of breath reduces activity, reduced activity further weakens muscles, and weakened muscles tire more quickly... ultimately leading to a body that is increasingly fatigued and breathless.

3. Has Your Body Truly Changed? VO₂max Actually Decreases.

These changes are not 'all in your head.' Multiple reports indicate that patients' VO₂max—maximal oxygen uptake—has decreased by an average of 10-30% after COVID-19. VO₂max literally refers to the maximum amount of oxygen your body can utilize in one minute. It is widely used not only as a measure of performance for marathon runners and athletes but also as an indicator of cardiorespiratory recovery and daily physical fitness for ordinary people.

Furthermore, research consistently confirms that after COVID-19, the efficiency of gas exchange in the lungs decreases, cardiac output is reduced, and the ability of muscles to utilize oxygen diminishes. Therefore, experiencing shortness of breath after climbing just a few flights of stairs and taking longer to recover than before are entirely natural responses.

4. Short of Breath and Fatigued, But Tests Come Back Normal?

They say tests are normal. Lung capacity, electrocardiogram, and blood tests all appear fine. Yet, you're still tired, short of breath, and your heart is pounding. In such cases, a dysfunction of the autonomic nervous system, specifically a syndrome called POTS, might come to mind. POTS stands for 'Postural Orthostatic Tachycardia Syndrome,' characterized by an excessive increase in heart rate when standing, accompanied by palpitations and fatigue.

What's surprising is that this can occur even in young, healthy individuals. It can appear suddenly after an infection, and recovery takes longer than expected. Since COVID-19 is a virus that can affect the lungs, heart, blood vessels, and nerves via ACE2 receptors, it's not uncommon for it to leave behind such multi-organ autonomic dysfunction.

5. Is This Unique to COVID-19?

Here's an interesting point: These symptoms existed even before COVID-19. There are numerous cases of fatigue, shortness of breath, delayed recovery, and autonomic dysfunction appearing after other viral infections like influenza, SARS (SARS-1), EB virus, and even the flu. The difference was simply that the number of patients was relatively small then, and there wasn't a sufficient system to track and study such cases.

This COVID-19 pandemic, an unprecedented event where hundreds of millions worldwide were simultaneously infected, brought to light post-illness recovery issues that were not well-observed before.

6. Traditional Korean Medicine Has Long Referred to This as Yeobyeong (Residual Illness)

Traditional Korean Medicine (TKM) has long recognized this as 'a state where the illness has ended, but recovery has not occurred,' referring to it as yeobyeong (餘病, residual illness) or byeonghuheojeung (post-illness deficiency syndrome). This is not a new concept; rather, it is quite thoroughly documented in ancient texts like the *Shanghan Lun* and *Jingui Yaolüe*.

For example, Juyeopseokgotang (Zhuye Shigao Tang in Chinese) is prescribed for those who 'have a persistent low-grade fever after illness, feel restless, and experience thirst.' In modern terms, this overlaps with key symptoms of long COVID, such as feeling hot but without fever, exhaustion, and irritability. Saengmaeksan (Shengmai San in Chinese) is used for those who 'have low energy, shortness of breath, a weak pulse, and spontaneous sweating.' This aligns with individuals experiencing persistent fatigue and poor heart rate recovery, characteristic of POTS or VO₂max-related fatigue.

Thus, Traditional Korean Medicine has long placed great importance on the distinction between 'being cured of an illness and the body fully recovering.'

7. There Are Specific Lifestyle Strategies to Aid Recovery

For these individuals, protecting the recovery system itself from overstimulation is paramount, rather than simply engaging in strenuous exercise or relying solely on medication. Strenuous exercise is strictly forbidden; it can actually delay recovery. Instead, 'pacing'—gradually increasing activity within the limits your body can tolerate—is crucial.

Adequate hydration and salt intake, maintaining a consistent sleep rhythm, and creating an environment that reduces stress also accelerate recovery. Even when using herbal medicine, the focus is not merely on supplementing energy but on stabilizing the flow of *qi*, regulating yin-yang imbalances, and restoring the body's defensive *qi* (wei qi).

8. The Illness is Over, But Recovery is Still Ongoing.

COVID-19 has ended. However, our body's recovery may not be over yet. Shortness of breath and fatigue are not signs of laziness or weakness, but rather an indication that your recovery system has been impacted and is still working to regain balance.

Symptoms after illness that were overlooked in the past—we now live in an era where we can observe, understand, and treat them more accurately. So, rather than self-blame, asking 'Why am I still like this when I'm supposedly cured?', I hope you'll view it from the perspective that 'recovery is not yet complete.' Your recovery is still in progress.

#LongCOVID #PostCOVIDSyndrome