Long Covid

15th August 2023 | Dr Melanie Dani and Dr Boon Lim


Long Covid is defined as persistent or new symptoms, attributed to Covid-19 infection, which last for more than 12 weeks after initial infection. They are often present earlier. Such symptoms may include fatigue, post-exertional malaise, breathlessness, chest pain, inability to exercise, palpitations, brain fog and fainting. However many more symptoms have been described and it is likely that the condition encompasses a range of different problems. This is the focus of global research activity currently. It is very common indeed, and has had major implications for society as it has left hundreds of thousands of people unable to work or exercise as before. As time goes on, we understand more and more about the condition, and possible underlying causes. It is likely that there may be multiple causes, and multiple underlying conditions. It can be scary and unpredictable, and often frustrating to find yourself in the situation where you are much ‘well’, or fit, than previously. It can also be overwhelming to read about new and constantly evolving ‘cures’ which can often be disappointing, so we advise sticking to trusted sites only.

Long Covid Symptoms

A common feature in Long Covid is orthostatic intolerance, or symptoms which are worse on standing, such as breathlessness, palpitations and chest pain. We have seen a rise in cases of seemingly new diagnoses of vasovagal syncope, POTS and orthostatic hypotension associated with Long Covid. We do not yet know enough about Covid-19 to speculate on why this is, but we know that the autonomic nervous system is involved in the body’s reaction to the virus infection. We also know that post-viral phenomena such as POTS and chronic fatigue are common, and it is likely that we are seeing such high numbers due to the high number of people involved in the pandemic.

There also appears to be an emerging link between hypermobility and autonomic dysfunction – you may wish to click on the following link to understand this more, if you feel that you may have hypermobility.

Covid and circulating volume - how does this affect the blood pressure and exacerbate symptoms of dizziness and fatigue?

Covid, or indeed, any other significant viral illess which creates and insult to the autonomic nervous system may lead to a “reset” of circulating volume and BP and heart rate control. This may be due to several factors, including acute deconditioning which may occur when being significantly ill for a number of days, and being less active, and having to rest and recover from illness. This deconditioning, (which may also be seen in astronauts returning from a zero-gravity spaceflight environment), may led to a shift in the blood pressure and circulating volume “set point” setting both of these values lower than baseline. As a result, you may find that your susceptibility to dizziness and fainting, particularly made worse in hot weather, whilst standing up or when dehydrated, increases immensely. Please check out this short video where Drs Lim and Dani speak more about the physical deconditioning and BP and circulating volume chances, which over time, can lead to chronic symptoms of orthsotatic intolerance, one of the common findings seen in long covid.


Autonomic dysfunction and Long Covid

What Can I Do?

Autonomic dysfunction is a very broad term which encompasses abnormalities in homeostasis (which means of self-regulating process by the body to maintain stability). The autonomic nervous system itself is that bit of the nervous system that regulates all the automatic functions which are not within conscious control such as blood pressure, heart rate, temperature regulation, sweating, peristalsis or gut contractility, urine production, and pupil dilatation. Think of the autonomic system as the master controller for all our subconscious bodily actions which maintains our day-to-day function without conscious sort of control.

We take this for granted most of the time and the autonomically system simply serves this and keeps his ticking along with an adequate blood pressure and heart rate to respond to day-to-day challenges, including stresses and strains, which elicits the fright or flight response (sympathetic nervous system activation), or resting and adjusting and rejuvenating which activates the vagus nerve (the parasympathetic nervous system). We can sometimes experience heightened states of autonomic shift, both towards the sympathetic nervous system, for example when we have an exam deadline or a job interview which compels us to increase energy levels to be able to stay awake and pulling all-nighters to complete the important task at hand. Equally we have also in life have been able to experience deep parasympathetic activation, for example when having long Sunday morning lie-in, feeling completely rejuvenated after refreshing 8 to 9 hours of sleep after a busy week. Some others practice intentional relaxation techniques such as yoga, breath work, meditation, can feel a sense of calm set into to your body -which is that feeling of restfulness mediated by activation of the vagus nerve.

Now imagine that chronic state of stress elevation both in terms of physical stress associated with the illness of acute COVID, together with the chronic stressors of long Covid symptoms, social isolation, inability to perform at work, or indeed at home with your family, and the uncertainty of recovery – all these factors provoke a chronic state in the autonomic system, which may be akin to preparing for the longest ever exam on job interview which can last 6 months or a year without any let-up or relief in all domains: physical, mental, and emotional. You may even questioning the very purpose of life, and how and why you got here, in this state so out of kilter from your normal pre-COVID self. 

Please do not despair, recovery is possible and with gentle steps, 1 day at a time, and with tools and techniques to rebalance the autonomic nervous system, it is possible to feel better. 

Below are some potential useful links to help guide your understanding of autonomic dysfunction in Long Covid and tips to improve your overall health and wellebing: 

The Long Covid Podcast with Jackie Baxter – Dr Boon Lim discusses autonomic dysfunction, the heart and long covid: 


Fixing your autonomic function in Long covid  (interview with Gez Medinger)


Some of you may have heard of tilt testing – which is a form of othostatic testing, essentially simulating a stand whilst being in a safe environment (ie tilt table clinic). There is a form of “tilt testing” that you can perform at home, called an active stand test. This is something you can do yourself with an upper arm cuff BP machine – which is something you can learn more about by clicking on the link (active stand test explained). 

However if you’d like to learn more about tilt testing,  do watch the video below  which shows examples of tilt table testing data, and what patients with autonomic dysfunction in long covid may experience during tilt testing. 


We have found that the steps we mentioned in the ‘tips and tricks’ section in the Dysautonomia section help symptoms in many cases – this is fundamental to recovery. At the moment, like other orthostatic intolerance disorders, there is no set ‘cure’ or magic bullet to cure the condition, but rather, a series of steps to gradually work on your symptoms.  It is important to pay careful attention to each step, ensuring stress reduction and gradual reintroduction of activity.  It is critically important to pace yourself, and allow yourself the time and space to get better. A useful way of thinking about this is to allocate yourself an ‘energy’ allowance for the day and plan your day accordingly, taking care not to use up all of your energy on one task and allow plenty of time for relaxation and rest. Try to space out essential tasks (such as household chores or going to the shops) throughout the week so that you do not do too much on one day. The key is to ensure you have regular gentle activity with plenty of breaks and rest, to allow your body to slowly upgrade what it can do.

In this video, Suzy  Bolt, a long covid patient herself, who runs a yoga for long covid recovery class (360mindbodysoul.co.uk), interviews Dr Boon Lim and Dr Melanie Dani to discuss Autonomic Dysfunction in Long Covid. 

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