What Are the Different Subtypes of POTS? (Key Symptoms)

Postural Orthostatic Tachycardia Syndrome (POTS) is not a single, uniform condition, but rather a “heterogeneous” disorder. This means that while all patients with POTS experience an excessive heart rate increase upon standing, the underlying causes in their bodies can be very different ^[1][2]. To better understand these differences, doctors categorize POTS into three primary subtypes: neuropathic, hyperadrenergic, and hypovolemic ^[3]. Knowing which subtype—or combination of subtypes—you have is important because it directly guides which medications and lifestyle changes will be most effective for you ^[4][5].

The Three Primary Subtypes

1. Neuropathic POTS

In neuropathic POTS, the small nerve fibers that control your blood vessels do not function correctly ^[6]. Normally, when you stand up, your nervous system tells the blood vessels in your legs and abdomen to tighten (constrict) so blood doesn’t pool in your lower body. In neuropathic POTS, this tightening is impaired, leading to blood pooling ^[6]. To compensate for the lack of blood returning to the brain, your heart beats much faster ^[7].

• Key signs: Patients often notice changes in the color of their lower legs or feet when standing, such as turning red, purple (acrocyanosis), or mottled ^[8].
• Treatment focus: Treatment for this subtype often involves vasoconstrictors—medications that force the blood vessels to tighten—along with physical counter-maneuvers (like tightly crossing your legs or clenching your thigh muscles) to manually push blood upward ^[7]. Doctors also recommend medical-grade compression garments; waist-high or thigh-high compression is generally needed, as calf-high socks often aren’t enough to prevent blood from pooling in the thighs and abdomen ^[7].

2. Hyperadrenergic POTS

Hyperadrenergic refers to an overactive sympathetic nervous system—your body’s “fight or flight” response ^[1]. When a person with hyperadrenergic POTS stands up, their body releases excessively high levels of the stress hormone norepinephrine ^[1]. This surge not only causes a rapid heart rate but can also cause blood pressure to rise when standing ^[9].

• Key signs: You may feel severe anxiety, tremors, sweating, or palpitations upon standing ^[10].
• Treatment focus: This subtype is typically managed with medications like beta-blockers or ivabradine, which lower the heart rate and block adrenaline receptors ^[1][11]. Importantly, patients with this subtype must usually avoid medications known as norepinephrine-reuptake inhibitors (SNRIs, common in certain antidepressants or ADHD medications) ^[1]. These drugs prevent the body from clearing out excess stress hormones, which can worsen the hyperadrenergic state ^[1].

3. Hypovolemic POTS

Hypovolemic means having an unusually low overall volume of blood circulating in your body ^[12]. Because there is less blood to go around, your heart has to pump faster to ensure enough oxygen reaches your brain when you stand up against gravity ^[1].

• Key signs: Worsening symptoms when dehydrated, especially in the heat or first thing in the morning ^[1].
• Treatment focus: Management heavily relies on aggressive “volume expansion” ^[1]. This means increasing your daily intake of fluids (often 2 to 3 liters daily) and salt (several grams daily, as directed by your doctor) to help your body retain water and build up blood volume ^[12]. Exercise training is also heavily emphasized to improve cardiovascular conditioning ^[1]. If lifestyle modifications are not enough, doctors may prescribe volume-expanding medications like fludrocortisone or desmopressin ^[7].

Mixed Subtypes Are the Norm, Not the Exception

If you feel like your symptoms fit more than one of these categories, you are not alone. It is extremely common for patients to have a mix of these subtypes rather than fitting perfectly into just one ^[1][13]. For example, low blood volume (hypovolemia) might trigger your nervous system to overreact (hyperadrenergic) ^[7]. Because of this overlap, treatments often need to be mixed and matched.

How Does My Doctor Figure Out My Subtype?

Because treatments differ so much between subtypes, comprehensive testing is important ^[5]. While a standard head-up tilt-table test or active stand test confirms the baseline POTS diagnosis ^[7], finding your specific subtype may involve:

• Catecholamine testing: Drawing your blood to measure norepinephrine levels while you are lying down and again after you have been standing for a few minutes ^[1]. Levels over 600 pg/mL upon standing often point to hyperadrenergic POTS ^[1]. Note: You may be asked to pause certain medications before this test so they don’t interfere with the results.
• Autonomic testing: Specialized tests like sweat tests (sudomotor testing) or breathing tests to check the function of your small nerve fibers ^[14].
• Skin biopsies: A small sample of skin may be taken to look for small fiber nerve damage ^[15].
• Blood pressure monitoring: Watching if your blood pressure drops, stays the same, or spikes when you stand ^[16].

Understanding your subtype is an important step in taking control of your condition. By tailoring your treatment—whether it’s managing salt intake, wearing compression, or finding the right medication—you and your doctor can work toward a plan that addresses the root causes of your symptoms ^[5].