Postural Orthostatic Tachycardia Syndrome (POTS) is a complex disorder of the autonomic nervous system, the body’s control system for involuntary functions like heart rate and blood pressure. Individuals with POTS experience symptoms, such as dizziness, lightheadedness, and an abnormally rapid heart rate, that occur primarily when transitioning to an upright posture like standing. Compression garments are a proven, non-pharmacological first-line defense used to manage these symptoms effectively. This therapeutic approach directly addresses one of the primary physiological challenges of the syndrome, offering a mechanical solution to a circulatory problem.
Understanding POTS and the Problem of Blood Pooling
The central issue in POTS is a form of orthostatic intolerance, meaning the body struggles to maintain proper circulation against gravity when a person stands up. Under normal circumstances, the autonomic nervous system triggers a rapid constriction of blood vessels in the lower body and abdomen to prevent blood from dropping downward. In POTS, this reflex often fails or is insufficient, which sets the stage for significant circulatory difficulty.
When standing, gravity causes blood to pool excessively in the veins of the lower extremities and the abdomen, a phenomenon known as venous pooling. This pooling reduces the amount of blood that successfully returns to the heart, which in turn lowers the heart’s filling pressure and the volume of blood it can pump out with each beat. This deficit of blood returning to the heart and, subsequently, the brain, is what triggers the body’s compensatory response.
The nervous system attempts to correct this problem by dramatically increasing the heart rate, a response called compensatory tachycardia, to rapidly circulate the diminished blood volume. While this rapid heart rate attempts to maintain blood flow to the brain, it is often insufficient and leads to the characteristic symptoms of lightheadedness, fatigue, and brain fog. Scientific studies suggest that the primary pooling mechanism is often due to blunted arterial vasoconstriction, which passively allows blood to collect in the veins.
How External Counter-Pressure Stabilizes Circulation
Compression garments function by applying external pressure to the body’s surface, providing a mechanical assist to the failing vascular system. This pressure physically squeezes the veins in the legs and sometimes the abdomen, which effectively reduces the internal space, or capacitance, within these blood vessels. By decreasing the capacity of the veins, the garments prevent them from expanding and holding large volumes of blood when gravity pulls it downward.
The mechanical squeezing directs the pooled blood back toward the central circulation—the heart and lungs—thereby increasing venous return. A greater volume of blood returning to the heart means a higher end-diastolic volume, allowing the heart to fill more completely. This improved filling directly translates to an increase in stroke volume, the amount of blood the heart pumps with each beat.
With a more efficient stroke volume, the heart does not need to beat as rapidly to maintain adequate blood flow to the brain and other vital organs. This stabilization helps to mitigate the compensatory tachycardia and the associated orthostatic symptoms, such as dizziness and palpitations. The sustained external counter-pressure acts as a functional replacement for the inadequate internal vasoconstriction reflex.
Choosing and Using Compression Garments Effectively
Selecting the right compression garment involves considering both the pressure rating and the length of the material, with pressure measured in millimeters of mercury (mmHg). For managing POTS symptoms, medical-grade compression is typically required, often starting in the range of 20 to 30 mmHg. Some individuals may require higher pressures, such as 30 to 40 mmHg, which often necessitates a medical prescription. Over-the-counter compression socks usually provide lower pressures that may not be sufficient for therapeutic needs.
The length of the garment is a crucial factor, as significant blood pooling occurs not only in the lower legs but also in the splanchnic circulation, the large network of veins in the abdomen. Therefore, waist-high compression tights or a combination of thigh-high stockings and an abdominal binder are often superior to knee-high socks alone. Full abdominal and lower body compression has been shown to be more effective at reducing heart rate and maintaining stroke volume during upright posture.
For maximum benefit, compression garments should be put on first thing in the morning, ideally before rising from a lying position, to prevent pooling from occurring at the start of the day. Proper sizing is paramount; garments should be professionally measured to ensure the pressure is applied correctly, as ill-fitting compression can be uncomfortable and less effective. Wearing them throughout the day while upright and removing them before bed establishes a routine that supports the body when it is most vulnerable to orthostatic stress.