There is a particular kind of tiredness that people with long Covid recognise instantly. It is not “I need an early night” tired. It’s not even an “I’ve overdone it” tired. It is a heavy, constant, body-wide exhaustion that doesn’t shift with rest and doesn’t make sense in proportion to what you have done, which by consequence has been very little. You can wake up and feel like you have already used up the day. Making a cup of tea can feel like a task that needs planning. A short walk can mean paying for it the next day, or the next week. That delayed crash, often called post-exertional malaise, is one of the most confusing and frustrating parts of long Covid.
For a long time, people experiencing this were left in a kind of limbo. Symptoms were real, persistent, and often debilitating, but explanations were thin. That gap has led to misunderstanding, dismissal, and in some cases, people questioning their own bodies. Now, the science may be starting to catch up.
The pattern is not entirely new. In the 1980s, a condition dismissed as “yuppie flu” was later recognised as Chronic Fatigue Syndrome. At the time, it was often framed as stress-related or exaggerated, but subsequent research linked many cases to post-viral illness, including infections such as Epstein-Barr virus. Decades on, ME/CFS is understood as a complex physical condition involving immune, neurological, and energy regulation dysfunction. The overlap with long Covid, particularly the same crushing fatigue and post-exertional malaise, is difficult to ignore and suggests that what is being uncovered now may be part of a much longer-standing pattern of how the body can respond to infection.
Recent studies are pointing towards a possible explanation that changes how we think about long Covid entirely: autoimmunity. In simple terms, the immune system may not be switching off properly after the initial infection. Instead of returning to normal, it continues to react and, in doing so, may start targeting the body’s own tissues.
This matters because it aligns closely with what many people are actually experiencing such as persistent fatigue, aches and pains, brain fog that makes simple thinking feel slow or fragmented. These are not random symptoms, but those consistent with how autoimmune responses behave in other conditions. Researchers, including Niels Eijkelkamp at Utrecht University, are exploring whether specific antibodies could be driving these symptoms. The idea is direct: if these harmful antibodies are removed, do the symptoms improve? It’s still early days, but this is one of the clearest, testable paths forward so far.
What makes this especially important is that long Covid has often been treated as a vague or catch-all condition. In reality, it may be several different mechanisms under one name. Autoimmunity could be one of the key drivers, particularly in people whose main symptoms are pain and fatigue.
Other research groups have reported similar findings. Some studies have identified abnormal immune markers months after infection. Others have found that parts of the immune system remain in a heightened state long after the virus is gone. There are also reports of microvascular changes and nervous system disruption, which could explain symptoms like dizziness, heart palpitations, and cognitive issues. Patient reports line up with this.
People describe needing to ration energy in a way they never had to before. A day out might mean two days recovering. Concentration can come and go unpredictably. Conversations that used to be effortless can feel like wading through mud. Even basic routines like shopping, cooking, or answering messages can become draining.
The unpredictability is part of what makes it so difficult. You can feel almost normal one day and then completely flattened the next, without a clear reason. That inconsistency can make planning life, work, and relationships extremely challenging.
In the UK, support groups and surveys have repeatedly shown that fatigue is one of the most common and persistent symptoms. Some people report gradual improvement over time. Others remain stuck in cycles of relapse and partial recovery.
Despite the scale of the problem, there are still no approved treatments specifically for long Covid in the UK or the US. Management is largely about symptom control, pacing, and trying to avoid triggering crashes. That leaves a gap between what people are experiencing and what medicine can currently offer. This is why the autoimmune theory matters. It moves long Covid out of the vague and into something measurable. Something that can be tested, targeted, and eventually treated. It also reinforces something that should not need reinforcing, but still does: this is physical. It is biological. It is happening in the body, whether or not it is visible from the outside.
For those living with it, especially with persistent tiredness, that recognition carries weight. It provides a framework that makes sense of the experience. Not a complete answer, but a direction.
There is still a long way to go. Research needs to confirm which patients are affected by these immune responses, how long they last, and what treatments are both safe and effective. But compared to where things were even a year ago, there is now a clearer sense of where to look.
Long Covid is not just the aftermath of an infection. For some, it is the result of a system that has not reset. And until it does, the exhaustion is not a lack of effort. It is the body still fighting something it no longer needs to fight and it’s so very debilitating …!
What Might Help: Supplements and Support
There is still no approved treatment for long Covid, however, some approaches used in post-viral fatigue and Chronic Fatigue Syndrome are being explored for symptom support, particularly around energy, inflammation, and recovery.
Magnesium is often used to support muscle function and reduce fatigue, especially where sleep is disrupted or muscles feel heavy and sore. Vitamin D is another common addition, particularly in the UK where deficiency is widespread and can contribute to low energy. (always remember to take this in the form of D3 and make sure it has the vit K too!)
B vitamins, especially B12, play a role in energy metabolism and nervous system function. Some people with persistent fatigue report benefit where levels are low or borderline. Coenzyme Q10 is also being studied for its role in cellular energy production, with some small studies suggesting it may help reduce fatigue in post-viral conditions.
Omega-3 fatty acids, found in fish oil, are linked to anti-inflammatory effects and may support overall immune balance. Similarly, antioxidants such as vitamin C and zinc are sometimes used to support recovery, although evidence in long Covid specifically remains limited.
The key point is consistency and caution. Supplements can support the body, but they are not a cure and should not replace medical advice. Effects, where they occur, tend to be gradual rather than immediate, so don’t give up!
For those dealing with ongoing tiredness, the most reliable foundation remains pacing, adequate rest, and avoiding the push-crash cycle. It’s boring having to plan your weekend with a day to recover, but fighting against this allocated rest won’t do you any favours…
