Postural orthostatic tachycardia syndrome (PoTS) is a complex clinical disorder primarily characterised by a marked increase in heart rate when transitioning from a reclined to an upright position. PoTS falls under the umbrella term of orthostatic intolerance. The term can be deconstructed etymologically:
Predominantly observed in developed nations, PoTS affects between 0.2% and 1.5% of the population, with a pronounced bias towards females, displaying a female-to-male ratio of 5:1, and it is more prevalent in individuals below 40 years of age (Raj, 2013).
Despite its classification as a disorder of the autonomic nervous system, PoTS is multifaceted, with patients experiencing a diverse range of symptoms and triggers. Given its association with the autonomic system, it invariably affects multiple bodily systems. This multifarious presentation, coupled with symptoms that are similar to those of other conditions, often results in a delayed diagnosis. Alarmingly, some patients are mislabelled as having psychiatric disorders such as panic disorders due to overlapping symptoms (Raj, 2013). Boris and Fischer (2024) noted that diagnosing PoTS is complex.
On accurate diagnosis, it becomes evident that PoTS profoundly affects a person's quality of life. Its episodic nature can be misleading as patients might seem healthy intermittently while grappling with severe incapacitation more generally. Although PoTS does not directly heighten mortality risk (Arnold et al, 2018), its functional debilitation is similar to chronic conditions such as chronic obstructive pulmonary disease and congestive heart failure, underscoring its severity.
Pathophysiology
In a healthy individual, the autonomic nervous system modulates heart rate and blood pressure to ensure optimal blood flow irrespective of the body's position. In individuals diagnosed with PoTS, there is an observable disruption in this regulatory mechanism, particularly in the co-ordination of vasoconstriction and cardiac rate response. Consequently, these individuals struggle to maintain a stable blood pressure, leading to many symptoms (Raj, 2013).
Physiologically, an upright posture results in gravitational sequestration of approximately 10% to 15% of the circulatory blood volume within the abdomen, legs, and arms. This redistribution results in reduced cerebral blood flow, potentially inducing transient light-headedness. In individuals without PoTS, such instances of light-headedness are infrequent due to the counteractive pumping action of the leg muscles, which aids in propelling blood towards the heart (National Institute of Neurological Disorders and Stroke, 2025).
Standing triggers the autonomic system to initiate a series of rapid compensatory mechanisms. Given the reduced venous return on standing, the system prompts the release of catecholamines, specifically adrenaline (epinephrine) and noradrenaline (norepinephrine). These hormones typically stimulate the heart to increase its rate and contractility. At the same time, noradrenaline induces vasoconstriction, facilitating enhanced blood supply to the heart and brain (Waugh and Grant, 2022).
Conversely, when moving to an upright position, PoTS patients tend to experience a more pronounced pooling of blood in vessels at a level below the heart. To counteract this, there is a greater release of noradrenaline and adrenaline, mainly aiming to intensify vasoconstriction. However, due to certain underlying factors, the vasculature in these patients does not respond typically to these hormones. The heart, still responsive to these catecholamines, often exhibits tachycardia. Such physiological dysregulation leads to a plethora of symptoms including dizziness, syncope and fatigue (Xu et al, 2016; Zhao and Tran, 2025).
Clinical presentation
PoTS may appear suddenly or evolve gradually. Symptoms typically manifest soon after assuming an upright position and often diminish when lying down. There is a range of symptoms, which can differ substantially between individuals (see Table 1).
| Symptom | Implications and significance |
|---|---|
| Dizziness after changing posture/standing | Disrupts daily activities; risk of injury due to falls |
| Brief loss of consciousness/near fainting | Safety risk, especially in uncontrolled environments |
| ‘Brain fog’, forgetfulness, concentration difficulties | Impacts productivity, social interactions, and quality of life |
| Heart palpitations, heightened heart rate | May lead to discomfort, anxiety and concerns over cardiac health |
| Severe tiredness | Affects day-to-day energy levels and the ability to complete tasks |
| Feelings of anxiety | Impacts emotional wellbeing and may exacerbate other symptoms |
| Trembling and excessive sweating | Physical discomfort and potential social self-consciousness |
| Shortness of breath | Impairs physical activity; may escalate to panic in severe instances |
| Chest discomfort | May lead to concerns over cardiac health and limit physical activity |
| Headaches | Can be debilitating, affecting mood and ability to function |
| Nausea | Affects appetite, nutrition and overall wellbeing |
| Bloating | Physical discomfort; may influence dietary choices |
| Facial pallor versus bluish tint to extremities | Indicates poor blood circulation; potential risk to extremities |
| Sleep disturbances due to nocturnal symptoms | Impacts overall health, energy levels, mood and cognitive performance |
Certain situations can exacerbate these symptoms, including hot environments, frequent standing, rigorous physical activity, concurrent illnesses and menstrual cycles (Xu et al, 2016; Zhao and Tran, 2025).
Underlying causes of PoTS
Recent research has further elucidated the subtypes and potential underlying causes of PoTS:
Diagnostic procedures
Diagnosing PoTS involves a comprehensive approach due to its varied presentations. See Table 2 for possible diagnostic procedures. The foundational diagnostic procedures include:
| Procedure | Purpose and relevance |
|---|---|
| Patient history and medication review | Provides context, identifies potential triggers, and reveals previous conditions or treatments |
| Physical examination | Direct observation for any visible anomalies or symptoms |
| Tilt table test | Gold standard for assessing cardiovascular response to positional changes |
| Blood and urine laboratory tests | Basic health assessment; identifies abnormalities that may point to or rule out PoTS |
| Quantitative sudomotor axon reflex test (QSART) | Evaluates the autonomic nerve control of sweating; crucial for diagnosing dysautonomia |
| Breathing tests | Assesses the autonomic function; helps identify dysregulation in the nervous system |
| Tuberculin skin test (TST) | Although not directly related to PoTS, this test can help rule out tuberculosis, which may present with symptoms that mimic those of PoTS |
| Skin nerve biopsy | Helps in diagnosing small fibre neuropathies, which can be associated with PoTS |
| Echocardiography | Assesses heart function and structure; essential since PoTS involves cardiovascular symptoms |
| Studies on blood volume and flow dynamics | Provides insights into blood circulation, which can be affected in PoTS and contribute to its symptoms |
Supplementary tests may include blood and urine analyses, autonomic function tests, and assessments of blood volume and flow dynamics to provide a comprehensive evaluation.
Other disorders leading to orthostatic intolerance
Although PoTS is a known cause of orthostatic intolerance, it is not the only disorder that can lead to these symptoms. It is vital for clinicians and patients to have a comprehensive understanding to avoid misdiagnosing other conditions as PoTS:
Treatment and management
Overview of therapeutic goals
The primary goals in treating PoTS are symptom relief and improving the patient's quality of life. Given the complexity and variability of the syndrome, a multidisciplinary approach is often necessary.
Pharmacological treatments
Pharmacological treatments are commonly used to manage PoTS symptoms. Beta-blockers, such as propranolol, are frequently prescribed to manage tachycardia by reducing heart rate. These medications are particularly beneficial for patients exhibiting elevated norepinephrine levels or a hyperadrenergic state (Fedorowski, 2019).
Corticosteroids, such as fludrocortisone, can help by increasing blood volume and improving blood pressure stability. Fludrocortisone achieves this by promoting sodium retention, thereby expanding blood volume, which can be advantageous for PoTS patients experiencing hypovolaemia (Rahman and Anjum, 2024).
Other medications that may be used include midodrine, a vasoconstrictor that constricts blood vessels to elevate blood pressure, and ivabradine, which specifically targets heart rate reduction without significantly affecting blood pressure. Ivabradine has been shown to improve symptoms in patients with PoTS by reducing the heart rate without affecting other cardiovascular functions (Taub et al, 2021).
Non-pharmacological strategies
Non-pharmacological strategies are essential in managing PoTS. These approaches include physical therapy, dietary modifications, and lifestyle adjustments (Cao et al, 2022):
Recent advances and experimental treatments
Recent research has explored novel treatment approaches for PoTS, including non-invasive nerve stimulation techniques. For instance, a recent study demonstrated that transcutaneous vagus nerve stimulation (tVNS) significantly reduced heart rate increase upon standing in PoTS patients, decreasing it by approximately 15 beats per minute. Additionally, tVNS was found to lower adrenaline surges and inflammation levels, contributing to symptom improvement (University of Oklahoma College of Medicine, 2024).
Ongoing research indicates that autoimmune mechanisms may contribute to PoTS; however, no definitive causative antibodies have been identified, and immunotherapies are not currently recommended (Aboseif et al, 2023). Clinical trials are under way to evaluate the potential efficacy of immunotherapies in PoTS patients (Eddy, 2022; Kesterson et al, 2023).
Management of co-existing conditions and complications
Many PoTS patients have co-existing conditions such as Ehlers-Danlos syndrome, chronic fatigue syndrome, or fibromyalgia, which can complicate treatment. It is crucial to manage these conditions concurrently to improve overall patient outcomes. Psychological support is also vital, given the high prevalence of anxiety and depression among PoTS patients.
Enhanced support for individuals with PoTS
Understanding and supporting individuals with PoTS is crucial due to the unpredictability of the condition. Close family and friends may struggle to comprehend the sudden loss of physical control and decreased autonomy, potentially straining relationships. Educational sessions aimed at close family members and carers can help bridge this gap by providing information about PoTS and its management. Recognising the emotional toll on supporters, they should also have access to support systems. PoTS UK currently offers peer support groups for parents and carers, which may be expanded to include all family members (visit https://www.potsuk.org).
The emotional impact of a PoTS diagnosis is significant, with many patients reporting feelings of isolation and distress even before receiving a formal diagnosis. Timely psychological support provided by professionals familiar with PoTS is essential. PoTS UK has introduced regional peer support groups, run by trained facilitators with lived experience, to address loneliness and provide emotional support.
Attending numerous medical appointments, particularly at different locations, can be challenging for PoTS patients. A co-ordinated approach to PoTS care, ideally within dedicated clinics, could improve access to consistent care. Additionally, increasing remote psychological support options can enhance patient engagement. Insights from patient experiences are shaping the development of digital resources, including an app focused on emotional support and lifestyle guidance for those with PoTS.
The nurse's role
Nurses play a critical role in patient care and recovery. Their direct interactions with patients give them a unique vantage point from which they can shape patient experiences. Understanding the nuances of specific conditions such as PoTS and their impact on patient experience and quality of life is imperative.
In essence, understanding the patient experience and quality of life implications in PoTS is not simply about improving care, but also about holistic healing. A well-informed, empathetic registered nurse can significantly impact the recovery journey, ensuring that care is not simply concerned with managing symptoms but with truly improving a patient's overall wellbeing.
Although registered nurses play a crucial role in providing compassionate and comprehensive care, it is important to differentiate between the responsibilities of general registered nurses and clinical nurse specialists (CNSs). Registered nurses may face challenges in providing in-depth clinical assessments due to limitations in specialised training, whereas CNSs are equipped with the advanced skills necessary to address the specific needs of these patients. By acknowledging these distinct roles, we can ensure that education and training are tailored appropriately, enabling both groups to contribute effectively.
Conclusion
Understanding the complexities and implications of conditions such as PoTS is paramount in the ever-evolving landscape of health care. Individuals with PoTS face a myriad of challenges, both physically and emotionally, which demand a holistic approach from health professionals. Moving forward, continuous research, education, and collaboration will be essential to creating a more patient-centred healthcare system within which individuals with PoTS feel understood, valued and adequately supported.