Postural Orthostatic Hypotension Syndrome (POTS)

What is Postural Orthostatic Hypotension Syndrome?

Postural orthostatic tachycardia syndrome (POTS) is a disorder of the autonomic nervous system that regulates involuntary functions like heart rate. In people with POTS, this system does not properly constrict blood vessels when standing up. This causes blood to pool in the legs rather than returning to the heart. As a result, the heart beats faster to compensate, sometimes increasing by over 30 beats per minute after standing.

Causes & Symptoms of Postural Orthostatic Hypotension Syndrome

The exact cause of postural orthostatic tachycardia syndrome (POTS) is not fully understood, but it is thought to be caused by a combination of factors. POTS can manifest through a wide range of symptoms, often overlapping with other conditions. These symptoms typically worsen when transitioning from lying down to an upright position. Daily functioning becomes impaired due to the unpredictability of symptoms.

Postural Orthostatic Tachycardia Syndrome (POTS) Causes

Dysfunction of the Autonomic Nervous System
POTS is closely linked to a malfunction of the autonomic nervous system, which regulates vital functions like blood pressure and heart rate. Irregularities in this system can disrupt normal circulatory responses.
Autoimmune Response
Emerging research suggests that an autoimmune process may affect blood vessels, causing excessive dilation when transitioning to an upright position.
Deconditioning
Extended periods of inactivity and muscle weakness can play a role in the development of POTS, contributing to symptoms.
Genetic Predisposition
While not directly inherited, certain gene variants may predispose individuals to developing POTS.
Triggers
POTS can be triggered by various factors, including viral illnesses, surgical procedures, pregnancy, injury, or trauma.

Postural Orthostatic Tachycardia Syndrome (POTS) Symptoms

Lightheadedness, Dizziness, or Fainting
When transitioning from lying down to an upright position, individuals with POTS often experience a sudden drop in blood pressure, leading to lightheadedness, dizziness, and in severe cases, fainting (syncope).
Heart Palpitations
POTS frequently results in a rapid heart rate, with the heart often beating more than 100 beats per minute upon standing. This palpitation is one of the defining characteristics of the condition.
Fatigue
Profound and persistent fatigue is a hallmark symptom of POTS, often disproportionate to an individual's level of physical activity. This fatigue can significantly affect daily functioning.
Cognitive Dysfunction
Many individuals with POTS report cognitive difficulties, including brain fog, difficulty concentrating, and memory problems.
Gastrointestinal Distress
Symptoms such as nausea, abdominal pain, bloating, and diarrhea can be troublesome for those with POTS.
Respiratory Issues
Shortness of breath and occasional chest pain may occur, particularly during upright posture.
Mental Health Symptoms
Anxiety, tremors, and sleep disturbances are common in individuals with POTS. The chronic nature of the condition, along with its unpredictable symptoms, can contribute to anxiety and emotional distress.
Thermal Regulation Issues
POTS can disrupt the body's ability to regulate temperature, leading to heat and cold intolerance. Excessive sweating may also be observed.

Testing & Diagnosis for Postural Orthostatic Hypotension Syndrome (POTS

Postural orthostatic tachycardia syndrome (POTS) shares symptoms with other medical conditions, such as dehydration, anemia, heart conditions, and anxiety disorders. Since POTS symptoms can be similar to other conditions, a full evaluation is needed to confirm a diagnosis. Some of the key tests used include:

Tilt Table Test
This is a specialized diagnostic test used to confirm POTS. During this test, you will be securely strapped to a table that can be tilted to various angles. Your heart rate and blood pressure are monitored continuously as you change positions from lying down to an upright tilt. An abnormal increase in heart rate upon standing is a defining characteristic of POTS.
Active Stand Test
This is similar to a tilt table test but simpler. You sit down for 5-10 minutes, then stand up unaided for 10 minutes while your heart rate and blood pressure are checked multiple times.
Physical Exam
Your doctor will listen to your heart, check your blood pressure lying down and standing, assess reflexes, muscle strength, and coordination.
Blood Tests
These help rule out other causes like anemia or thyroid disorders. Common blood tests include complete blood count, metabolic panel, erythrocyte sedimentation rate, and thyroid levels.
Autonomic Reflex Screening
This assesses how your involuntary nervous system responds to certain stimuli like breathing exercises or the Valsalva maneuver. Abnormal responses may indicate dysautonomia.