What you need to know about POTS (Postural orthostatic tachycardia syndrome)

From the desk of
Luis Villaseñor
ScienceWhat you need to know about POTS (Postural orthostatic tachycardia syndrome)

Anywhere from 500,000 to 3 million Americans have a condition called POTS: postural orthostatic tachycardia syndrome. For people with POTS, standing up causes a rapid increase in heart rate. This can lead to a variety of other symptoms such as dizziness, brain fog, and nausea.

The symptoms of POTS are generally attributed to a lack of proper blood flow to the brain. Upon standing, blood stays settled in the lower half of the body for too long. This causes the heart to beat faster to compensate.

The precise underlying causes of POTS, however, are both puzzling and highly variable. In fact, the syndrome appears to be a group of separate disorders, united only by their symptoms. Women are about five times more likely to have POTS than men, and it’s also more common in adolescents.

Thankfully, a handful of treatments show promise for POTS. One of these treatments, interestingly enough, is to eat more salt. Consuming more salt can increase one’s blood volume, which makes it easier for the heart to get blood to the brain.

That’s just one method of managing POTS — this article will cover other strategies, as well as what POTS is, what might cause it, and how it’s diagnosed. Let’s get straight to it.

What Is POTS?

Postural orthostatic tachycardia syndrome is a mouthful. Let’s take it one word at a time:

  • Postural: Refers to the position of your body
  • Orthostatic: To be caused by an upright posture, or standing up
  • Tachycardia: Rapid heart beat
  • Syndrome: A condition characterized by a set of associated symptoms

When you break it down, it makes sense. POTS is a set of symptoms that occur when someone stands up. The hallmark of POTS is the rapid heartbeat, but a range of non-specific symptoms may also present, including headache, dizziness, brain fog, blurry vision, heart palpitations, tremors, nausea, and even fainting.

POTS Diagnosis

The gold standard for diagnosing POTS is the tilt table test. To take this test, you lie on a table that moves from horizontal to vertical, simulating the action of standing up. The person administering the tilt table test monitors the patient for an increase in heart rate over the course of 5 to 30 minutes. Alternatively, doctors can check for rapid heartbeat by having the patient stand without assistance after lying flat on their back.

To be diagnosed with POTS, the patient’s heart rate must increase by at least 30 beats per minute in adults, or 40 beats per minute in adolescents. However, POTS diagnosis is only made after several other conditions have been ruled out, such as dehydration, reaction to medications, and orthostatic hypotension.

What Causes POTS?

Cerebral hypoperfusion, or reduced blood flow to the brain, is probably the biggest driver of POTS symptoms. Less blood flow, less oxygen, more symptoms.

The triggering event is standing up because when people stand, blood gets pulled away from the brain and briefly pools in the lower half of your body. To compensate, hormones — like norepinephrine and epinephrine — are secreted to shuttle more blood into the upper half of your body. But it appears that people with POTS don’t respond normally to these hormones.

Despite POTS patients recording blood levels of norepinephrine three times greater than those without POTS, blood flow to their brain remains inhibited. Without sufficient blood flow to the brain — and because adrenal hormones independently affect heart rate — the heart often responds by beating faster.

Why does this system break? That’s where things get hazy. There isn’t just one type of POTS, there are several. These include:

  • Hypovolemic POTS: Related to low blood volume.
  • Hyperadrenergic POTS: Related to an excess of the adrenal hormones epinephrine and norepinephrine, both of which increase heart rate.
  • Neuropathic POTS: Related to damage of the nerves that regulate blood vessels.
  • Secondary POTS: Related to some other cause, like Lyme disease, diabetes, or autoimmune disease.

But the story doesn’t end here. Let’s discuss hypovolemic POTS a bit more.

Sodium for POTS

Sodium is an electrolyte found in salt (sodium chloride). One of its most important jobs is to regulate fluid balance inside and outside of your cells. And consuming sodium increases blood volume, which helps blood reach all throughout your body, including your brain.

Since many hypovolemic POTS patients have shown low levels of renin and aldosterone — your sodium retention hormones — it makes sense that consuming sodium could help restore their blood volume. The practical question remains: Does getting more salt improve POTS symptoms?

It appears that it can! Research suggests that intravenous saline can help restore blood volume in people with POTS, leading to a reduction in heart rate and mitigating blood pressure fluctuations. That said, it’s not very fun to walk around with a personal IV.

Thankfully, simply eating a high-salt diet and drinking salty water have both been shown to be effective treatment for people with POTS and similar conditions such as orthostatic hypotension (OH). You can mix your own sodium beverage at home, consume sodium-rich foods like pickles and olives, or try a high-sodium electrolyte drink mix like LMNT.

Other Treatments For POTS

Along with consuming more salt, increasing fluid intake can help boost blood volume and alleviate POTS symptoms. One needs to be careful, however, not to drink too much sodium-free water. This can dilute blood sodium levels and make matters worse.

Some lifestyle changes may also reduce POTS symptoms. It’s been shown that aerobic exercises like jogging, cycling, and swimming can help with POTS. Just be sure to hydrate with fluids and electrolytes. Other behavioral alterations include sleeping with your head elevated, standing with crossed legs, and avoiding long periods of standing.

Finally, a number of medications are commonly prescribed for POTS, including:

  • Beta-blockers may help POTS patients with high adrenaline, but not POTS patients with low blood pressure.
  • Fludrocortisone increases blood volume by increasing salt and water retention.
  • Erythropoietin increases blood volume and red blood cell mass.
  • Vasoconstrictors tighten blood vessels to prevent blood pooling in the lower body.

If you have POTS, work with your doctor to come up with a holistic treatment plan. Some of these medications have side effects which shouldn’t be taken lightly.

POTS Summary

Here’s a quick recap of what you just learned about postural orthostatic tachycardia syndrome, or POTS:

  • Up to 3 million Americans may have POTS, and the distribution skews toward adolescents and women.
  • When an adult has POTS, their heart rate increases by at least 30 bpm within 5–30 minutes of standing. Adolescents’ heart rate increases by at least 40 bpm.
  • Other POTS symptoms include fatigue, dizziness, headache, difficulty concentrating, and nausea.
  • POTS is generally attributed to low cerebral blood flow.
  • The underlying causes of POTS may include poor response to hormones like norepinephrine, low blood volume driven by low renin and aldosterone, high adrenaline levels, diabetes, or other conditions.
  • Increasing sodium intake, which increases blood volume, has been shown to alleviate symptoms of hypovolemic POTS.
  • Other POTS treatments include drinking more water, exercise, behavioral changes, and several classes of drugs.

If you or a loved one has POTS, I hope this article has given you some meaningful ways to manage symptoms. Please share these learnings with others to help them too.

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