Gravity's Enemy: Understanding POTS and Dysautonomia.

Every time you stand up, gravity pulls a significant amount of blood into your lower body. In a healthy person, the autonomic nervous system — the unconscious control center that manages heart rate, blood pressure, digestion, and temperature — detects this shift instantly. It signals the blood vessels to constrict, pushing blood back upward to keep the brain and heart properly supplied.

For someone with Postural Orthostatic Tachycardia Syndrome (POTS), that signal doesn't arrive quickly enough, or with enough force.

POTS is the most common form of Dysautonomia — an umbrella term for conditions involving autonomic dysfunction. In POTS specifically, the autonomic system has a significant gap in its cardiovascular response to standing. The good news: the heart itself is structurally healthy. Understanding what's actually happening is the first step toward managing it.

What's Actually Happening When You Stand

When a person with POTS stands up, the blood vessels in the lower body don't constrict fast enough. Blood pools in the legs and lower abdomen — sometimes visibly, as a deep flush or mottled color in the feet and lower legs.

To prevent fainting from insufficient blood flow to the brain, the body launches a compensatory response: a surge of adrenaline that tells the heart to beat faster and harder to push blood upward. This is why the heart rate spikes so dramatically. It's not a heart problem — it's the heart doing its best to compensate for a vascular system that's not holding up its end of the deal.

The result is something that feels like a full "fight or flight" response triggered by simply standing in line at the grocery store. Your body isn't overreacting — it's working overtime.

How POTS Is Diagnosed

POTS has a precise clinical definition. It's not diagnosed by the feeling of dizziness alone — it's measured. A cardiologist or neurologist uses a Tilt Table Test or a structured standing test (sometimes called the "Poor Man's Tilt Table") to formally confirm it.

The criteria: An adult must show a sustained heart rate increase of at least 30 beats per minute (BPM) within 10 minutes of standing, without a significant drop in blood pressure (which would suggest a different form of dysautonomia). For adolescents, the threshold is 40 BPM.

For many patients, 30 BPM is actually a conservative floor. It's not unusual for someone's resting heart rate of 70 BPM to spike to 130, 140, or higher just from brushing their teeth upright. That number, while alarming, is also validating — because it's proof.

Beyond the Heart Rate: The Full Symptom Picture

Tachycardia is the most measurable symptom, but it's rarely the only one. Because the autonomic nervous system influences so many body systems, POTS can show up in ways that seem completely unrelated — which is part of why it often takes years to diagnose. Some common associated symptoms include:

• Lightheadedness and near-fainting: Chronic dizziness, tunnel vision, and presyncopal "graying out" when upright. Some patients also experience full fainting episodes.
• Digestive effects: The digestive system is autonomically regulated, and POTS can affect gut motility — leading to nausea, bloating, and delayed gastric emptying (gastroparesis). Severity varies widely between patients, and symptoms often improve as POTS management improves.
• Temperature regulation difficulties: Trouble staying warm or cool, inappropriate sweating, and heat sensitivity. Dysautonomia affects the body's thermostat.
• Brain fog: Reduced blood flow to the brain while upright can cause real cognitive effects — word retrieval issues, difficulty concentrating, and memory gaps. This is physiological, not psychological.
• Coat hanger pain: Aching or burning across the shoulders and neck, caused by muscles working hard to hold the head upright when blood flow to those tissues is reduced.

The "Deconditioning" Myth

For years, many patients were dismissed as simply "deconditioned" or anxious. This was wrong, and the medical community has largely moved past it. While prolonged bedrest can make POTS symptoms worse, deconditioning does not cause POTS.

Who Helps Diagnose and Treat POTS?

If you suspect POTS, the most common starting points are a cardiologist, neurologist, or an autonomic specialist. Some electrophysiologists and dysautonomia clinics also evaluate POTS. A primary care doctor can help start the process by documenting orthostatic vitals and writing the referral.

Useful things to bring to that appointment: a symptom timeline, resting and standing heart rate logs if you have them, blood pressure readings, medication lists, known triggers, family history, and notes about fainting, near-fainting, heat intolerance, GI symptoms, or post-viral onset.

Treatment is individualized, but common tools include fluids, sodium when appropriate, compression garments, careful exercise or cardiac rehabilitation, trigger management, and medications that may support blood volume, improve blood vessel tone, or calm excessive heart rate. This is not one-size-fits-all medicine. POTS has subtypes and causes, and the right plan depends on the person in front of the doctor.

What Does This Diagnosis Mean?

A POTS diagnosis means your orthostatic symptoms are measurable. It means the racing heart, dizziness, exhaustion, shaking, nausea, and brain fog have a physiological pattern. That matters. But POTS is a syndrome, not a complete root-cause explanation.

POTS does not usually come out of nowhere. It can appear or worsen after acute viral illness (including COVID-19), physical trauma, surgery, pregnancy, long periods of bedrest, or major physiological stress. It can also travel with underlying conditions such as Ehlers-Danlos Syndrome, mast cell activation, small fiber neuropathy, autoimmune disease, or other disorders that affect blood vessels, nerves, immune signaling, or connective tissue regulation.

That does not mean every patient has the same cause. It means the diagnosis is often the beginning of the investigation, not the end of it. Once you know your body is struggling with orthostatic regulation, the next questions become clearer: Why is my blood pooling? Is my blood volume low? Are my vessels constricting properly? Did this start after an infection? Do I also have signs of EDS, MCAS, neuropathy, anemia, autoimmune disease, or medication effects?

Gravity is working against you, but it is not the whole story. With the right clinician, the right testing, and a treatment plan built around your body, many people with POTS reclaim meaningful function and quality of life.

Stay Salty!