Disclaimer: Please note that this guide is intended for informational purposes only and should not be used in place of medical advice. If you have a medical condition or diagnosis, be sure to consult with your doctor or a member of the healthcare team.
If you stand up and feel dizzy, or feel as though you are swaying, or shaky, or short of breath, or feel as though you are about to faint then you are not dreaming it and you are not daft.
Orthostatic Intolerance (OI) is a condition which affects many people with Long Covid and is not yet widely recognised, and the many symptoms it brings can be easily written off or dismissed as unimportant.
Standing for any length of time can bring on quite a range of really unpleasant symptoms, some of which can feel frightening or very difficult to cope with. These include feeling very tired or dizzy or as though you have been turned round and round in a vortex or that the room is whirling round you. You may feel shaky, light headed, or short of breath or that you are going to faint. Your skin may go clammy, your heart may race, you may feel sweaty, nauseous, or very tired or aching.
Dysautonomia is a common underlying condition for many symptoms. POTS or Postural Orthostatic Tachycardia Syndrome is a subcategory of the overall group of dysautonomia conditions. Understanding your body and how it works in relation to your dysautonomia, POTS and Long Covid is a key part of getting a proper diagnosis and feeling better.
There are many treatment options available to treat and manage the symptoms of dysautonomia and POTS and we include Long Covid protocols in some of our treatments here at The Apheresis Center.
When the Autonomic Nervous System Goes Wrong
The autonomic nervous system (ANS) is the involuntary or unconscious part of the nervous system. The ANS is responsible for controlling the body’s involuntary or automatic functions such as heart rate, blood pressure, body temperature, digestion and respiration.
The Autonomic Nervous System (ANS) is responsible for controlling many of the bodies involuntary actions. In dysautonomia, the ANS does not function correctly and so the body is unable to adapt smoothly to environmental changes that most people take for granted such as standing from low height to a high height, changes in temperature or light or being able to tolerate light exercise.
What systems are affected by Long Covid and the ANS?
Some of the bodily systems that are affected include:
- Microclots obstruct blood flow to important organs and tissues
- Endothelial damage to blood vessels
- Chronic inflammation
- The presence of autoantibodies that interfere with neural communication between neurons in the PNS and CNS
Researchers estimate that between two thirds to nearly all Long Covid patients have moderate to severe autonomic dysfunction despite appearing normal on standard autonomic function tests. Dysautonomia is a common reason why some people don’t feel better despite the fact that they have Long Covid and recovered from their initial case of Covid-19.
For a deeper dive into the actual biology of Long Covid & Dysautonomia, read our article “Why You Still Feel Sick: The Hidden Biology of Long Covid. ”
POTS: The Most Common Form of Dysautonomia in Long Covid
What is POTS?
Postural Orthostatic Tachycardia Syndrome (POTS) is a type of dysautonomia. It is a condition in which there is a marked increase in heart rate in response to postural changes, specifically when moving from a lying to a standing position, despite not experiencing a drop in blood pressure.
In adults, a POTS pattern is defined as an elevation of 30 beats per minute (bpm) or more, and/or a heart rate that exceeds 120 bpm within 10 minutes after assuming a standing position, accompanied by associated symptoms.
In POTS, the blood vessels in the legs are not able to constrict in response to standing. When you stand, blood pools in your legs and abdomen instead of being returned to the heart and brain. In an attempt to counteract the blood pooling in the legs, the body tries to pump more blood which leads to tachycardia, palpitations and what is referred to as “adrenergic overdrive”. This is not related to being deconditioned or being anxious. It is related to the body’s physiologic response to standing upright.
How Common is POTS After Covid?
POTS and other forms of orthostatic intolerance are becoming increasingly common diagnoses in many of the long Covid clinics that have opened up around the world. A number of studies that looked at the most symptomatic patients with long Covid have found POTS or clear orthostatic intolerance in 15-50% of those with postural symptoms. The figures vary depending on the patient population and the criteria for diagnosis. One of the larger studies looking at 65 patients referred for assessment of autonomic function found that a third had POTS.
Important note:
Some people with POTS find that they develop the condition weeks, months or even sometimes 6-8 months after they have begun to feel better from the initial underlying infection.
It does not appear to correlate with the severity of your acute Covid. Most of you were just a bit tired and yucky for a couple of weeks.
About 40% of POTS cases occur after a viral infection, so this connection to SARS‑CoV‑2 isn’t surprising.
Recognising the Symptoms
Common POTS Symptoms
People with POTS often say that their body “falls apart” when they are upright. Some symptoms include:
- Debilitating fatigue, often worse after being upright or after minimal exertion
- Dizziness, lightheadedness, or near‑fainting on standing
- Rapid heartbeat or palpitations
- Chest discomfort or tightness
- Headaches or head pressure
- Nausea and sometimes abdominal discomfort
- Brain fog, slowed thinking, or difficulty concentrating
- Tremulousness or internal shakiness
- Weakness, especially in the legs
- Visual changes such as blurred vision, greying, or tunnel vision
- Sweating, temperature sensitivity, or chills with position changes
These are also common with other Long Covid symptoms, which is why POTS is often missed.
When Symptoms Occur
Orthostatic intolerance symptoms typically:
- Are triggered by moving from lying or sitting to standing
- May appear immediately or build over several minutes of being upright
- Improve (sometimes dramatically) when you lie back down or elevate your legs
- Matters can deteriorate in hot weather, after a hot shower or bath, after meals, with dehydration, or after over-exertion.
Lots of people with COVID experience heat intolerance as well as worsening POTS symptoms that coincide with one another. We just published a paper about heat intolerance and how to manage heat intolerance-related flares.
POTS vs Other Forms of Orthostatic Intolerance
Orthostatic intolerance is a collection of symptoms that occur in response to standing and being upright. POTS is a form of orthostatic intolerance.
POTS: Heart rate increase of ≥30 bpm within 10 minutes after assuming an upright position and while symptoms are present; BP response may be variable but is typically non-proportional to the degree of heart rate elevation.
Orthostatic hypotension (OH): A fall in blood pressure that is statistically and physiologically significant (≥20 mmHg drop in systolic blood pressure) that occurs upon assuming a postural change to a standing position and is associated with symptoms of dizziness or syncope and, most often, a relative bradycardia.
It is very important to try to find out what type of seizure is occurring, as the treatment and medicines may be different.
Why Does Covid Cause POTS?
We don’t yet fully understand all of the mechanisms involved and there is considerable research underway to further understand and refine the valid, but largely overlapping, mechanisms that have been identified in the scientific literature.
Hypovolemia (Low Blood Volume)
Lots of patients post Covid are showing low ECV which is called hypovolemia. This low ECV can occur secondary to the inflammation caused by the virus as well as edema redistribution and sedentary lifestyle seen during Covid. If a patient has decreased venous return due to standing, then the heart rate increases in order to generate enough cardiac output to meet the body’s demands. This is also characteristic of POTS.
Neurotropism and Nerve Injury
There is a possibility that SARS‑CoV‑2 can directly injure nerves and the small autonomic fibres such as those involved with heart rate and blood vessel function. A number of case series and biopsy studies suggest that up to 50% of patients with POTS may develop SFN symptoms, including burning pain, tingling and other autonomic manifestations. Infections may also predispose to and trigger POTS through other mechanisms including dysregulation of the endothelial vasculature, damage to the smooth muscle and the innervation and effects on immune cells on vessel walls that contribute to abnormal vessel constriction and dilation.
Inflammation and Immune Activation
Symptoms of long COVID are caused by chronic low-grade inflammation characterized by persistent elevations of pro-inflammatory markers and cytokines. This inflammation leads to decreased heart rate variability and increased autonomic dysfunction. The body then becomes ‘stuck’ in a predominantly sympathetic (fight or flight) state causing tachycardia and leading to increased sensitivity to stressors such as heat and postural changes.
Autoimmunity
Autoantibodies against GPCRs & other proteins related to vascular tone & heart rate are common in POTS patients with & without Covid19. Targets may include adrenergic, muscarinic, and angiotensin receptors among others. The antibodies may interfere with receptor function affecting vasoconstriction, heart rate & other components of the autonomic dysfunction seen in POTS. POTS also coincides more frequently with other autoimmune diseases which also supports an immune-related pathophysiology.
Additional Contributing Factors
- Deconditioning from prolonged bed rest or reduced activity
- Mitochondrial dysfunction affects energy production
- Endothelial dysfunction and persistent microclots leading to compromised oxygen delivery to the brain and nerves
There are many factors involved in Orthostatic Intolerance. The following are some of the most significant and those that have been the subject of considerable research.
- Microclots: Small blood clots that cause a reduction in blood flow to various areas of the body.
- Inflammation: This is caused by an overactive or underactive immune system and is associated with the release of harmful chemicals.
- Autoantibodies/Autonomic Dysfunction: Autoantibodies are abnormal antibodies that the body mistakenly attacks the functioning cells of the autonomic nervous system.
Getting a Diagnosis
Clinical Assessment
The journey starts with listening to your story. A full assessment for suspected Long Covid POTS would include the following:
- A full medical history to understand the current state of your health and how it is affecting you.
- A full medical examination to assess your physical condition.
- Specialised blood tests to assess the inflammatory processes at play.
- ECG and heart rate monitoring to assess the heart’s activity.
- Blood pressure checks both lying and standing to assess blood pressure regulation.
- An assessment of your urine output to assess kidney function.
- Autonomic function tests (including deep breathing, Valsalva and 30:15 ratio) to formally diagnose POTS.
- A comprehensive exercise test to assess your body’s physiological response to physical stress, particularly your heart rate and blood pressure responses.
- Detailed history focusing on orthostatic symptoms, triggers, and recovery.
- Cardiovascular, respiratory, and neurological examination
- Vital signs taken lying, sitting, and standing
- Screening for other serious complications of Covid (pulmonary embolism, myocarditis, organising pneumonia) where appropriate
We also look for other contributing factors such as ME/CFS-type post-exertional malaise, mast cell activation symptoms, and small fibre neuropathy.
Diagnostic Tests
Two key tests are commonly used in POTS and orthostatic intolerance:
- Heart rate and blood pressure are measured from rest in a supine position, and at intervals after standing (for example, 1, 3, 5 and 10 minutes). An increase in heart rate of ≥30 bpm, or a fall in blood pressure without clinical symptoms, confirms the diagnosis of POTS.
- Head-up tilt table test. This is the test of choice in many centres. This involves the patient being seated on an electrically powered tilt table. The table is then gradually tilted up to an angle of between 60° and 80° head-up and cardiac rhythm and blood pressure are recorded for any abnormalities such as tachycardia, hypotension and syncope.
Additional investigations may include:
- 24–48 hour ECG or Holter monitoring
- Blood tests to assess for anaemia, thyroid dysfunction, infection, and electrolyte issues
- Autonomic function testing (for example, Valsalva manoeuvre, deep breathing tests)
- Sudomotor or skin biopsy testing when small fibre neuropathy is suspected
Why POTS is Often Missed
We’ve noticed that the symptoms of POTS are so easily masked and therefore mistaken for other conditions such as anxiety, deconditioning and post-viral fatigue syndrome. The autonomic nervous system is not taught to any great degree in medical school so doctors are not even aware of the possibility of dysautonomia and therefore do not routinely measure orthostatic changes in blood pressure or perform an active stand test when examining a patient.
So when all the investigations come back normal – as they inevitably do – the doctor can reassure the patient that there is nothing wrong. Not true.
The first step to quality care for Orthostatic Intolerance (OI) is public recognition that OI is a real, identifiable condition.
POTS and Related Long Covid Conditions
Overlap with ME/CFS
Both involve fatigue, post-exertional malaise, sleep disturbances and orthostatic intolerance. There’s a ton of information on the autonomic dysfunction associated with ME/CFS that’s being applied to long Covid management. Advice for managing both includes: All activity and rehabilitation must be carefully individualised and delivered at a high intensity to avoid triggering post-exertional malaise (PEM) – as opposed to being delivered as part of a graded exercise therapy programme.
Connection to Other Dysautonomias
There are many patients with Long Covid who will not fit neatly into the ‘pure’ criteria for POTS. This paper provides some insight into the problems that can occur. First there are those with a mixed profile of symptoms who have some features in keeping with POTS but also other features which suggest other diagnoses such as OHT or vasovagal syncope. Then there are those with a broader spectrum of autonomic dysfunction whose symptoms include temperature regulation problems, gut dysmotility, bladder symptoms and incontinence and other hyperhidrosis.
Mast Cell Activation Syndrome (MCAS)
We have seen flushing, hives, itching, stomach issues and food or chemical sensitivities pop up more and more in patients with Long Covid. We are also seeing it with POTS. It is actually being researched more and more in the medical community with a lot of research being done on immune and inflammatory responses to disease and how these are very similar in MCAS and POTS and how each can be triggered by similar things such as heat, stress, and infections. Taking medication to decrease the activation of mast cells (like antihistamines, that can be prescribed by your doctor) has been a huge tool in helping to decrease Orthostatic Flare ups.
Living with POTS: Practical Tips
Medical therapy is important but non-medical interventions can also have a large impact. Here are some general recommendations that were given to me by a dysautonomia specialist:
- Pacing and energy management ideas: Break tasks into smaller steps, rest when feeling tired, rather than when exhausted. Use a heart-rate monitor to discover your individual zone of fitness and exercise and activity levels within this zone.
- Hydration and salt (if needed): Encourage patients to drink more fluid and to increase salt intake as advised by healthcare providers to increase blood volume. pmc.ncbi.nlm.nih.gov
- Compression: High compression class (waist-high) stockings and/or abdominal binders may be used to help reduce blood pooling in the legs and abdomen.
- Heat management tips: Take a shower less often and have a cooler shower. No hot tubs, saunas or steam rooms. No tanning bed. If you need to be in the open air when it’s extremely hot, stay in an air-conditioned space or in the shade.
- Food & nutrition: A smaller, more frequent feeding schedule may help to stabilize blood glucose levels and may be beneficial to some patients. Please ask a member of staff at the Apheresis Center for further information.
Support If you feel comfortable, you may wish to inform your employer or school about your condition. Many people find joining a patient support group to be very helpful. They can be a valuable source of information and a powerful way to connect with others who share similar experiences.
Prognosis and Recovery
Overall prognosis for Long Covid POTS is mildly to moderately good. Patients with post-Covid POTS were seen to improve significantly over time with more than 90% having a reduction in their symptoms of a similar magnitude by around 5 months. There is a vast degree of variability of speed of recovery and some can recover in weeks whilst others in years with a slow but steady reduction in their symptoms.
Key points from current research and clinical experience:
- Early recognition and tailored treatment are linked to better outcomes.
- Youthful individuals generally have a quicker recovery, yet this therapy is not exclusive to the young.
- Postural Orthostatic Tachycardia Syndrome (POTS) is not necessarily associated with severe acute Covid.
- Long Covid POTS can be a bit different to the POTS that existed pre-pandemic, and studies are ongoing to confirm the long term manifestations of this condition.
When to Seek Help
You should seek urgent medical care immediately if you experience:
- Loss of consciousness or prolonged fainting
- Severe chest pain or pressure
- Severe or rapidly worsening shortness of breath
- Symptoms suggestive of blood clots (for example, painful swollen leg, sudden breathlessness)
These can indicate serious complications that need emergency evaluation. A Specialist assessment e.g. from cardiology, neurology or Long Covid clinics with a good understanding of dysautonomia may be required in the following situations:
- Orthostatic symptoms persist despite self‑management
- Your quality of life, work, or education is significantly impaired
- The diagnosis is unclear or you have multiple overlapping conditions
- You are considering medications or advanced therapies and need coordinated care
How The Apheresis Centre Approaches Long Covid POTS
We see conditions such as Postural Orthostatic Tachycardia Syndrome (POTS) and other forms of dysautonomia as secondary to an initial insult to the body such as the formation of microclots, endothelial damage and/or autoimmune dysfunction.
Our approach to testing for conditions such as POTS therefore involves an assessment of the presence of microclots and the presence of autoantibodies such as GPCR AABs where applicable. A full assessment of inflammatory markers is also performed alongside a full clinical history and physical examination with assessment of mitochondrial dysfunction.
Therapeutic Apheresis is not routine and is rarely recommended for any patients.
- H.E.L.P. Apheresis removes fibrin-rich microclots, spike protein complexes and inflammatory mediators to restore microcirculation and improve oxygen delivery to tissues.
- Apheresis Spherectomy (INUSpheresis) or immunoadsorption procedure to remove specific autoantibodies, pathogens or toxins as needed.
Our program includes complementary therapies such as IV micronutrients, nutrition support and hyperthermia (when applicable, following our Cyprus Protocol).
These treatments are not primary and therefore should not be used as a replacement for traditional medical care. They are not suitable for all patients. They will be considered on an individual basis only following a full assessment and should not be used in place of first line POTS management strategies with any local medications that may have been prescribed by your family doctor.
Your Next Step
It’s very frustrating and very chaotic trying to get on with life with POTS and Orthostatic Intolerance (OI) post Covid. It’s very easy to have it constantly dismissed and diminished to ‘anxiety’ without any regard for the fact that there are real physiological symptoms and very real solutions. First step is always to raise awareness of the fact that there is a physiological cause behind the suffering.
If you identify with the Long Covid description and are experiencing symptoms associated with dysautonomia and POTS, you may benefit from a more detailed evaluation and treatment plan.
Talk with your doctor about POTS and orthostatic testing (active stand or tilt-table).
Author / Medical Review Note
Written by: Andrew Smith. Reviewed by our Medical Director, Dr Inbar Tofan. Dr Tofan is an Internal Medicine Doctor with over 15 years’ clinical experience. She is an expert in the administration of therapeutic H.E.L.P. apheresis and the management of highly complex and chronic post-viral conditions including Long Covid and dysautonomia.
Key References
pmc.ncbi.nlm.nih.gov/articles/23156592 pmc.ncbi.nlm.nih.gov/annotations/PMID:34364321/figure/F4 pmc.ncbi.nlm.nih.gov/articles/PMC8973312/
