POTS, or postural orthostatic tachycardia syndrome, is a condition where your heart rate spikes abnormally when you stand up. The diagnostic threshold is an increase of 30 beats per minute or more (40 or more for teenagers) within 10 minutes of standing, without a significant drop in blood pressure. POTS affects an estimated 1 to 3 million people in the United States, predominantly women of childbearing age.
What Happens in Your Body
Every time you stand up, gravity pulls about 500 milliliters of blood from your chest down into your legs and abdomen. On top of that, 10 to 25 percent of your plasma volume shifts out of your blood vessels and into surrounding tissue. Normally, your autonomic nervous system catches this immediately: it releases adrenaline and norepinephrine, which speed up your heart slightly, tighten your blood vessels, and push blood back up to your brain and heart. You barely notice it.
In POTS, this compensatory system malfunctions. The blood pools excessively in the lower body, and the brain responds by flooding the system with more signals to speed up the heart. The result is a heart rate that races upon standing, often reaching 120 beats per minute or higher, while blood pressure stays roughly the same. The rapid heart rate is the body’s attempt to compensate for poor blood return, not a heart problem itself.
The Three Main Subtypes
POTS isn’t a single condition so much as a pattern that can arise from different underlying problems. Most specialists recognize three subtypes, though overlap is common.
- Neuropathic POTS is the most common form. About half of patients have damage to the small nerve fibers that control blood vessel constriction in the legs and feet. Because those nerves can’t tighten the vessels properly, blood pools in the lower body and the heart has to work harder to compensate.
- Hypovolemic POTS involves chronically low blood volume. Up to 70% of POTS patients have lower-than-normal blood and plasma volume. Paradoxically, the hormones that should tell the kidneys to retain fluid don’t function correctly in these patients, so the body fails to correct the problem on its own.
- Hyperadrenergic POTS is driven by an overactive fight-or-flight response. Patients have elevated levels of norepinephrine (at least 600 pg/mL while standing) and their systolic blood pressure rises by 10 mmHg or more upon standing. This subtype tends to produce more prominent anxiety, tremor, and palpitations.
Symptoms Beyond a Fast Heart Rate
The racing heart is the defining feature, but most people with POTS experience a constellation of symptoms that can be disabling. Lightheadedness, dizziness, and near-fainting upon standing are the most obvious. Many people describe a feeling of the room going gray or their vision narrowing when they get up too quickly.
Cognitive impairment, commonly called “brain fog,” is one of the most frustrating symptoms. It can involve difficulty concentrating, trouble finding words, and a general mental sluggishness that worsens with standing or exertion. Fatigue is nearly universal and often severe enough to interfere with work or school. Other common symptoms include palpitations, headaches, blurred vision, shortness of breath, gastrointestinal problems like bloating and nausea, and sleep disturbance.
Who Gets POTS
About 94% of POTS patients are female, and the most common age of onset is 14. The condition disproportionately affects adolescents and young women. Many patients report that symptoms began after a specific trigger: a viral infection, surgery, pregnancy, or a period of prolonged bed rest.
The COVID-19 pandemic brought significant attention to POTS. Research shows the incidence rate jumped from about 1.4 per million person-years before the pandemic to 20.3 per million afterward, roughly a fourteenfold increase. Many of these new cases appear as part of long COVID, where the virus seems to damage the autonomic nervous system.
Common Co-Occurring Conditions
POTS rarely travels alone. Up to 18% of POTS patients also have Ehlers-Danlos syndrome (EDS), a connective tissue disorder that causes joint hypermobility and fragile skin. The connection likely runs through the autonomic nervous system: the same connective tissue abnormalities that make joints overly flexible may also affect blood vessel walls, making them too stretchy to constrict properly.
Gastrointestinal problems are especially common in this overlap group. Reflux, bloating, abdominal pain, and delayed stomach emptying (gastroparesis) significantly impact quality of life. Mast cell activation syndrome, migraines, and autoimmune conditions also appear at higher rates in the POTS population.
How POTS Is Diagnosed
Diagnosis typically starts with one of two tests: an active stand test or a tilt table test. Both measure how your heart rate and blood pressure respond to being upright.
For an active stand test, you lie flat for a period and then simply stand up while a clinician monitors your heart rate and blood pressure at intervals over 10 minutes. It’s straightforward and can be done in any office. The tilt table test is more controlled: you’re strapped to a table that tilts you to about 60 degrees, simulating standing without letting you use your leg muscles. This removes the muscle-pumping effect and can provoke a more dramatic response. Both tests look for the same threshold: a heart rate increase of 30 beats per minute (40 for teens) without a large blood pressure drop.
One important nuance is that tilt table tests tend to produce more false positives than active stand tests. In one comparison study, 80% of healthy control subjects met the 30 bpm threshold during a 30-minute tilt, versus 47% during a 30-minute stand. This means clinicians need to interpret results carefully and consider symptoms alongside the numbers.
Lifestyle Changes That Help
For most POTS patients, increased fluid and salt intake is the first recommendation. Drinking about two liters of water and consuming three to five grams of salt daily helps expand blood volume and reduce symptoms (though the hyperadrenergic subtype may need a different approach). Compression garments, particularly waist-high stockings or abdominal binders, help prevent blood from pooling in the legs and abdomen.
Exercise is one of the most effective long-term treatments, but it requires a specific approach. Standard upright exercise like running or standing weightlifting can trigger severe symptoms early on. The recommended strategy starts with horizontal exercises: rowing, swimming, or a recumbent bike. Patients typically begin training three to four times per week for 25 to 30 minutes per session. Over the first two months, duration and intensity gradually increase. By the end of the second or third month, upright exercise like walking on a treadmill or jogging is added. By month three, the goal is five to six sessions per week lasting 45 to 60 minutes each. This progressive approach avoids the crash-and-burn cycle that discourages many patients from exercising at all.
Medications for POTS
When lifestyle changes aren’t enough, several types of medication target different aspects of the syndrome. Low-dose beta blockers slow the heart rate directly, reducing palpitations and tremor. A medication that constricts blood vessels (midodrine) is considered the most studied and effective option for reducing dizziness and fainting, and it works particularly well for the neuropathic subtype by counteracting the blood pooling in the legs.
For patients with low blood volume, a synthetic hormone (fludrocortisone) helps the kidneys retain more salt and water. A newer heart-rate-lowering medication (ivabradine) has shown promise for the hyperadrenergic subtype because it slows the heart without lowering blood pressure the way beta blockers can. For brain fog specifically, stimulant medications have helped some patients, with one study finding that 77% of patients with treatment-resistant POTS reported significant improvement in fatigue and near-fainting episodes.
Treatment is highly individual. Because the subtypes involve different mechanisms, a medication that works well for one patient may be ineffective or even counterproductive for another. Most people end up on a combination of lifestyle modifications and one or two medications, adjusted over time based on which symptoms are most disabling.