How does POTS cause Brain Fog?

POTS (Postural Orthostatic Tachycardia Syndrome) can cause a variety of symptoms. One of the most common ones (and personally, most frustrating ones) is brain fog.

What is Brain Fog?

Brain fog is described as “cognitive dysfunction”, in areas such as thinking, remembering, concentrating, and reasoning to a level that interferes with daily activities. (1) According to Vanderbilt’s Autonomic Dysfunction Clinic, 80-90% of POTS patients report brain fog as a symptom. Vanderbilt describes brain fog as “difficulty thinking, concentrating, or paying attention; trouble remembering things; cloudy or fuzzy feeling in head; and having problems finding the right words.” According to Dysautonomia International ,this can occur even while patients are lying down or seated, which limits their ability to attend school or to work.

How Does POTS Cause Brain Fog?

When a person stands up, gravity naturally pulls our blood down into the lower half of our bodies.

In a healthy individual, the body is able to compensate for this and push blood back up to the heart and the brain. In POTS and other Dysautonomias, there is a malfunction in the body’s ability to do this (for a variety of reasons). As such, blood instead pools in the lower extremities. Simply put, there isn’t enough blood getting up to the brain.

In POTS, there can be two reasons why this doesn’t happen:

1. Low blood volume (there’s not enough blood, so it can’t reach all the way up)

2. Loose blood vessels (lack of constriction doesn’t push blood back up)

Sources:

1. Dysautonomia International https://dysautonomiainternational.org/blog/wordpress/cognitive-dysfunction-and-brain-fog-in-pots/#:~:text=One%20of%20the%20most%20common,that%20interferes%20with%20daily%20activities.