Could a Dysregulated Nervous System Be Causing Your Fatigue?

The ANS runs our background settings, including heart rate, blood pressure, breathing, body temperature, and digestion, so we don’t have to think about them. When the ANS malfunctions, it may lead to symptoms of dysauto­nomia, in which ordinary activities like standing or taking a hot shower become strangely depleting.

“Right now, there’s an epidemic of dysfunction in the ANS,” notes functional-medicine physician Gregory Plotnikoff, MD, MTS, FACP. “We have more and more people with impaired capacity to literally stand up.”

The ANS has two primary branches: the sympathetic, also known as “fight or flight,” and the parasympathetic, usually called “rest and digest.” (It also encompasses the enteric nervous system in the gut.) Communication between the sympathetic and parasympathetic systems helps manage blood flow to the brain.

“Right now, there’s an epidemic of dysfunction in the ANS,” Plotnikoff notes. “We have more and more people with impaired capacity to literally stand up.”

When the balance between the two is off, blood can pool in the legs, and the heart races in an effort to get enough blood to the brain. “If you don’t get good brain perfusion, you’re going to be fatigued; you’re going to feel weak; you’re going to feel like you need to lie down,” Plotnikoff says.

When people with ANS dysfunction do lie down to rest, their brains get adequate blood flow, and suddenly they feel wired and unable to sleep. Adds Plotnikoff, “This is a very common thing that drives a multibillion-dollar-a-year insomnia industry.”

Signs of ANS dysfunction can include lightheadedness upon standing, graying vision that clears upon sitting, a racing heart, breathlessness, brain fog, or the odd combo of feeling tired but wired. Testing can include electrocardiograms, physical or neurological exams, and tilt-table tests that measure how different body positions affect heart rate.

How to address:

Fixing nervous-­system imbalances that lead to poor blood flow to the brain can often effectively take care of symptoms, Plotnikoff says. Tools might include diet changes, exercise, or medication. “Suddenly, people’s brain fog is gone, and their ­clarity, capacity, and energy are significantly improved.”