When Standing Up Makes You Sick

Experts are not sure why, but it’s a condition that tends to strike young women, aged 15-35, most often from comfortable, and white, families. This fits my roommate’s situation. It may be that POTS could be found in other segments of society, but neither patients nor doctors are making the connection.

The root cause of POTS lies in the body’s remarkable automatic control system – the autonomic nervous system – which manages heart rate, blood pressure, circulation, digestion, and temperature control.

When we stand, gravity pulls blood toward our legs. A healthy nervous system immediately responds. Blood vessels tighten, the heart adjusts, and enough blood continues to reach the brain.

In someone with POTS, that response does not work properly. The body struggles to maintain circulation when upright, and the heart often speeds up dramatically to compensate.

The result can be dizziness, fatigue, weakness, exercise intolerance, difficulty concentrating, and a pounding heartbeat. Some sufferers feel better when they lie down – but not all. When the autonomic nervous system is out of whack, all bets are off.

Historically, and to date, many patients have struggled to find an explanation. Because routine heart tests and blood work may appear normal, some are told their symptoms are due to stress or anxiety.

During the American Civil War, physician Jacob Mendes Da Costa described soldiers who suffered from racing hearts, fatigue, chest discomfort, and poor exercise tolerance.

The condition became known as “soldier’s heart.” Although it was not the same diagnosis as POTS, researchers believe these individuals may have had problems involving the autonomic nervous system.

Over the decades, doctors continued to encounter patients who became ill when upright. But it was not until the 1990s that researchers formally described and named POTS.

Scientists now understand that POTS is not one single disease. Different patients may have different underlying causes. In some, nerves that regulate blood vessels may not function properly. In others, there may be abnormalities involving the immune system, blood volume, or the body’s response to infection.

The COVID-19 pandemic brought unprecedented attention to POTS. Some people recovering from COVID developed persistent symptoms including rapid heart rate, dizziness, and exercise intolerance. Researchers began investigating whether viral infections could trigger autonomic disorders in susceptible individuals.

Although POTS is often associated with younger people, it can occur at any age. In older adults, symptoms may be mistaken for medication effects, dehydration, heart problems, or the normal challenges of aging.

For my roommate and her daughter, and similar to many other families, it was a long and frustrating journey to the diagnosis of POTS. Ultimately, it took a team of specialists at the Mayo Clinic to design and initiate a four-week intensive program of physical, mental, and behavioural changes to daily routines that enabled them to return to normal life.

With better knowledge about what’s going on, there comes an appreciation for the extraordinary things the human body does, even when just standing up.