Educational articles about neurological conditions and what actually works

Written by our team to help you understand complex neurological conditions and our diagnostic approach.

POTS treatment options, from beta blockers and ivabradine to salt, exercise and brain-first rehab
POTS & Dysautonomia Testing & Diagnosis Brain Blood Flow
POTS

Does Salt Help POTS? How Much Salt and Water to Take

Does salt help POTS? See the consensus doses for salt and water, what studies show about how much and how fast, and what salt and water can miss.

Dr. Nathan Keiser
POTS

What Causes the High Heart Rate in POTS?

What causes the high heart rate in POTS? The heart speeds up to rescue blood flow to your brain. Why it happens, what beta blockers reveal and what to measure.

Dr. Nathan Keiser
Dysautonomia

Dysautonomia Physical Exam: The Bedside Neurological Tests

The bedside neurological exam our team pairs with autonomic testing: pulses, reflexes, eye movements, and what each reveals about POTS and dysautonomia.

Dr. Nathan Keiser
POTS

POTS Fluid Dumping: Why Salt and Water Aren't Enough

For most people with POTS, low blood volume is not the core problem. Here is why salt and water hit a ceiling, and what fluid dumping really means.

Dr. Nathan Keiser
POTS

Can POTS Be Cured? What the Research and Our Clinical Experience Actually Show

Can POTS be cured? Many recover significantly or fully. 'Cure' means recalibrating a nervous system that lost its precision, and research shows it can.

Dr. Nathan Keiser
POTS

Why POTS Wrecks Your Digestion (And Why GI Doctors Can't Find the Problem)

Why POTS and dysautonomia cause nausea, bloating, and gastroparesis. The gut isn't broken; the brain's control of it is. The autonomic-GI connection.

Dr. Nathan Keiser
Dysautonomia

Hypocapnia in Dysautonomia: Hypocapnic Cerebral Hypoperfusion (HYCH)

Hypocapnia (low CO2) narrows brain arteries. On standing, that's HYCH: POTS symptoms without the heart rate jump. Here's how the clinic tests and treats it.

Dr. Nathan Keiser
Dysautonomia

Orthostatic Cerebral Hypoperfusion Syndrome: When Your Brain Loses Blood Flow but Every Test Looks Normal

Orthostatic cerebral hypoperfusion syndrome (OCHOS) is a measurable drop in brain blood flow on standing. Learn how it differs from standard POTS.

Dr. Nathan Keiser
POTS

How Functional Neurology Fits POTS Care

POTS is a brain regulation problem, not a heart rate problem. Mechanism-based neurological evaluation identifies what's actually driving symptoms.

Dr. Nathan Keiser
POTS

Intensive POTS Treatment Programs

What intensive POTS treatment involves: cerebral blood flow testing, vestibular rehab, and neurological rehabilitation. What to expect in 4 to 7 days.

Dr. Nathan Keiser
Dysautonomia

Your Tests Came Back Normal. You're Clearly Not.

Free guide: the 4 mechanisms your doctors aren't testing for, and how to find which one is keeping you sick. From The Keiser Clinic.

Dr. Nathan Keiser
Dysautonomia

Ear Fullness and Popping in POTS: The Drainage Problem Behind It

Ear fullness, popping, or a heartbeat in your ear with POTS? It often traces to how blood drains from your head, not just your eustachian tubes.

Dr. Nathan Keiser
Vestibular

Dizzy in Elevators? What It Reveals About Your Vestibular System

Feeling dizzy in an elevator isn't random. It's a small test of how your brain blends vision, inner ear, and body sense to keep you balanced.

Dr. Nathan Keiser
Dysautonomia

Derealization and POTS: Why You Feel Detached From Reality

Feeling detached from reality with POTS or dysautonomia? Derealization is often a blood-flow and vestibular signal, not just anxiety. What it means.

Dr. Nathan Keiser
Dysautonomia

POTS Symptoms: Why They Don't Match Your Autonomic Test Results

A 2024 study of 2,627 patients found POTS and dysautonomia symptom surveys don't match objective autonomic testing. Here's what that gap really means.

Dr. Nathan Keiser
Dysautonomia

POTS vs OCHOS: Why the 30 BPM Line Doesn't Mean What You Think

POTS and OCHOS share one core problem: reduced cerebral blood flow. The 30 BPM threshold dividing them is a 40-year-old artifact, not a biological boundary.

Dr. Nathan Keiser
Vestibular

When Gravity Feels Wrong, Everything Feels Overwhelming

A 3-degree error in gravity perception made everything feel overwhelming. How the vestibular system shapes anxiety, brain fog, and sensory overload.

Dr. Nathan Keiser
Vestibular

Why Vestibular Dysfunction Causes Anxiety, Brain Fog, and Depression

Vestibular dysfunction doesn't just cause dizziness. When the brain's spatial reference breaks down, it drives anxiety, brain fog, depression, and fatigue.

Dr. Nathan Keiser
Dysautonomia

Peripheral Nerve Stimulation for Dysautonomia: Train the Brain Without Crashing

Peripheral nerve stimulation lets dysautonomia patients train the brain without crashing. How PNS restores proprioception and cerebral blood flow.

Dr. Nathan Keiser
POTS

The Three Types of POTS

POTS isn't one thing. Understanding the three subtypes, neuropathic, hyperadrenergic, and hypovolemic, is the first step toward treatment that works.

Dr. Nathan Keiser
Dysautonomia

POTS Without the T: When You Have Every Symptom But Don't Qualify

If your blood pressure looks normal and your heart rate doesn't quite qualify, you've been told nothing is wrong. Here's what the standard test misses.

Dr. Nathan Keiser
Dysautonomia

Why So Many Dysautonomia Patients Are Misdiagnosed and Mistreated

A POTS diagnosis can be a relief, but for many the treatments still don't work. Here's why, and what understanding your specific mechanism changes.

Dr. Nathan Keiser
Dysautonomia

Low CO2: Symptoms, Causes and What It Does to Brain Blood Flow

Low CO2 narrows brain arteries and cuts blood flow. Here are the symptoms, the causes, how it's measured on a tilt test and what the research says about raising it.

Dr. Nathan Keiser
Dysautonomia

Transcranial Doppler (TCD) Test: What It Shows in POTS

A transcranial Doppler tracks how fast blood moves to your brain as you're tilted upright, and shows whether it drops in POTS and by how much.

Dr. Nathan Keiser
Neurology

What Part of the Brain Controls Eye Movements?

Eye movement testing shows which brain circuits may be underperforming. See what jumpy tracking can mean, one patient's story, and how our team uses it.

Dr. Nathan Keiser
Concussion

Post-Concussion Syndrome Treatment: What Helps When Symptoms Last

Concussion symptoms that won't fade? What post-concussion treatment targets, where rest fits, how activity returns and what the research shows.

Dr. Nathan Keiser
Vestibular

Vestibular Dysfunction: Symptoms, Tests and Our Team's 5 Types

Vestibular dysfunction means your balance system isn't working right. Our team's 5 working types, how each is tested, and why symptoms can outlast normal tests.

Dr. Nathan Keiser
Dysautonomia

Autonomic Testing for POTS: What Each Test Measures

Autonomic testing for POTS checks heart rate, blood pressure and sweat nerve reflexes. Learn what each test measures, what results mean and what they miss.

Dr. Nathan Keiser
Migraine

Migraine as a Neurological Event: A Different Approach

Migraine is a neurological event, and the headache is only one part of it. Treating migraine as a brain problem instead of a pain problem opens new treatment pathways.

Dr. Nathan Keiser
Neurology

Neck Problems and the Brain: 7 Ways Your Neck Drives Brain Fog, Dizziness and POTS

Neck problems can cause brain fog, memory trouble, dizziness and POTS symptoms. See the 7 ways cervical joint errors reach the brain and how they're tested.

Dr. Nathan Keiser
Dysautonomia

Small Fiber Neuropathy and POTS: How SFN Drives Dysautonomia

Small fiber neuropathy shows up in a quarter to half of POTS patients tested. How SFN drives dysautonomia, why a skin biopsy can miss it, and what improves it.

Dr. Nathan Keiser
Neurology

Brain Fog Causes: Why It Gets Worse When You Stand or Drive

What causes brain fog, why it can get worse when you stand or drive, and how to find which link in your brain's supply chain is weak.

Dr. Nathan Keiser
Dysautonomia

POTS Exercise Intolerance: Symptoms, Causes and What Helps

Why exercise feels so hard with POTS: the symptoms, what research shows about the heart and fitness, what our team finds in the brain, and what helps.

Dr. Nathan Keiser
Neurology

Can Tight Neck Muscles Restrict Blood Flow to the Brain?

Tight muscles, posture and the bones of your neck can squeeze the arteries to your brain. What research shows, who gets symptoms, and how our team tests it.

Dr. Nathan Keiser
Dysautonomia

Is IV Saline the Cure for ME/CFS and Dysautonomia?

IV saline helps ME/CFS and dysautonomia patients feel better temporarily. But if the problem is blood flow distribution, saline is a patch, not a fix.

Dr. Nathan Keiser
Dysautonomia

How to Actually Diagnose Chronic Fatigue Syndrome

ME/CFS isn't just fatigue. How chronic fatigue syndrome is properly diagnosed, what testing reveals about the brain, and why finding the mechanism matters.

Dr. Nathan Keiser
Dysautonomia

How to Reverse PEM for Good (ME/CFS Recovery)

PEM recovery explained: what a PEM crash is, how long it lasts, why it often hits a day or more later, and how our team works to widen what you can do.

Dr. Nathan Keiser
Neurology

FND and POTS: How They're Linked and How to Tell Them Apart

FND and POTS can show up together. What FND is, how it differs from POTS, why standing can make FND symptoms worse, and what a tilt test can show.

Dr. Nathan Keiser
Neurology

Cerebral Hypoperfusion: Why Your Brain Isn't Getting Enough Blood

Cerebral hypoperfusion means too little blood reaching the brain. What hypoperfusion is, symptoms, causes, why normal blood pressure misses it, and tests.

Dr. Nathan Keiser
Dysautonomia

Why Most Dysautonomia Treatments Don't Work

Why do so many dysautonomia treatments fail? Both conventional and functional medicine miss the one core problem: the brain is the common thread.

Dr. Nathan Keiser
Dysautonomia

Can Vitamin Toxicity Be Causing Your POTS?

Can B6 toxicity cause POTS? Learn about vitamin B6 and autonomic nerves, how to start moving again with POTS, and hypoplastic vertebral arteries.

Dr. Nathan Keiser
Dysautonomia

POTS: When Your Brain Loses Its Balance

POTS isn't just about heart rate. Learn why it's really a brain coordination problem, and why treating it as a heart condition misses the mechanism.

Dr. Nathan Keiser
Dysautonomia

Blood Pooling in Your Legs, Hands and Feet: What Causes It

Blood pooling is blood collecting in your legs, feet or hands when you stand. What it looks like, why ankles swell, when it's normal, and its POTS causes.

Dr. Nathan Keiser
POTS

Why Does My Heart Race When I Stand Up?

Your heart races when you stand because your brain is losing blood flow, a measurable regulation failure, not anxiety. Here's what's actually happening.

Dr. Nathan Keiser
Dysautonomia

POTS vs Deconditioning: Can Deconditioning Cause POTS?

Does deconditioning cause POTS, or POTS cause deconditioning? What bed rest does to the heart, POTS vs being out of shape, and what exercise can and can't do.

Dr. Nathan Keiser
Dysautonomia

Sleep, Neuroplasticity, and POTS: Why Your Brain Needs Sleep to Heal

Sleep is actively restorative. Learn why sleep is the engine of neuroplasticity and recovery in dysautonomia and POTS.

Dr. Nathan Keiser
Neurology

Proof That the Brain Controls the Autonomic System

Proof that the brain controls the autonomic system, using eye movements, cerebral blood flow data, and real patient outcomes from targeted brain rehab.

Dr. Nathan Keiser
Case Study

Case Study: POTS and Digestion Problems Solved Together

A 21-year-old with POTS and gastroparesis improved digestion, heart rate, and sensation through neural rehab, without any GI-specific treatment.

Dr. Nathan Keiser
Case Study

Case Study: 2 Years of POTS Resolved in One Month

A patient with two years of POTS recovered in one month through targeted neural rehab: cerebral blood flow testing, tilt progression, and retinal slip.

Dr. Nathan Keiser
Case Study

EDS and POTS: Back to Life in Less Than a Month

Case study: A college-aged EDS and POTS patient went from missing school and extreme fatigue to getting back to life in under a month.

Dr. Nathan Keiser
Case Study

POTS Treatment Case Study: From Housebound to Coaching Again

POTS case study: A 21-year-old athlete went from housebound to coaching baseball and taking classes again. Neuropathy findings and CO2-guided rehab.

Dr. Nathan Keiser
Dysautonomia

Hyperadrenergic POTS: Symptoms, Causes and Treatment

Hyperadrenergic POTS (hyperPOTS) is POTS with a norepinephrine surge on standing. See the symptoms, how it's tested, what beta blockers miss and what to check.

Dr. Nathan Keiser
Case Study

Diagnosed With POTS, But That Wasn't the Problem

A 15-year-old diagnosed with POTS wasn't actually a POTS case. See the real diagnosis, brain-based treatment, and full recovery including return to school.

Dr. Nathan Keiser
Concussion

Solving Post-Concussion Symptoms That Wouldn't Go Away

Post-concussion case study: dizziness, heart rate spikes, nausea, and broken sleep. See the eye findings, treatment steps, and outcome.

Dr. Nathan Keiser
Case Study

Are People With POTS Permanently in a Wheelchair? An 8-Year Case

She had POTS for 8 years and used a wheelchair daily. See what our team found on exam, how we treated her and what changed within a couple weeks.

Dr. Nathan Keiser
Dysautonomia

SSRIs and POTS: Do They Help or Make It Worse?

Do SSRIs help POTS? What the one randomized SSRI trial found, why SNRIs and ADHD drugs can raise standing heart rate, and how to talk with your prescriber.

Dr. Nathan Keiser
Dysautonomia

POTS vs Anxiety: How to Tell Which Is Causing Your Symptoms

POTS or anxiety? How to tell which comes first, why POTS is so often misdiagnosed as anxiety, what testing shows, and a case where the body led.

Dr. Nathan Keiser
Dysautonomia

What Doctors Are Missing in POTS Cases

Why so many POTS cases get dismissed, why clean labs don't mean you're fine, and how a brain-first approach finds what standard workups miss.

Dr. Nathan Keiser
Dysautonomia

How to Know If Your POTS Is Actually Improving

How to know if your POTS is actually improving using cerebral blood flow data, not just symptoms. A case study shows why BP meds may worsen perfusion.

Dr. Nathan Keiser
Dysautonomia

Orthostatic Intolerance: Symptoms, Types and What Causes It

Orthostatic intolerance means symptoms when you stand that ease when you lie down. Symptoms, causes, and the types: orthostatic hypotension, POTS and OCHOS.

Dr. Nathan Keiser
Case Study

POTS Recovery After 2 Weeks of Treatment

A 27-year-old with brain fog and POTS after a concussion recovered cerebral blood flow and resolved heart rate instability in two weeks.

Dr. Nathan Keiser
Neurology

What Is Functional Neurology, and Is It Legitimate?

Functional neurology measures a function, gives a targeted input and retests. How it differs from neurology, its training and what the evidence shows.

Dr. Nathan Keiser
Neurology

Your Brain's Secret Blood Flow Control System

Your brain has its own blood flow control system. Learn why that matters for POTS and why normal blood pressure doesn't guarantee normal brain blood flow.

Dr. Nathan Keiser
Dysautonomia

Tilt Table Test for POTS: How Long It Takes, Nitroglycerin and Results

What happens on a tilt table test for POTS, how long it takes, why some labs give nitroglycerin, what the results mean and whether you need one at all.

Dr. Nathan Keiser
Dysautonomia

MCAS and Dysautonomia: How Mast Cells and POTS Connect

How MCAS and dysautonomia connect: what histamine does to blood flow and heart rate in POTS, how to tell the 2 apart, and what helps when both flare.

Dr. Nathan Keiser
Dysautonomia

Recalibrate, Don't Just Manage

POTS and dysautonomia treatment should recalibrate your nervous system, not just manage symptoms. Targeting the lynchpin unlocks recovery.

Dr. Nathan Keiser
Neurology

Why Your Diagnosis Label Might Be Holding You Back

CFS, POTS, and ME/CFS syndrome labels describe symptoms, not causes. Moving from syndrome to mechanism is the key to effective treatment.

Dr. Nathan Keiser
Dysautonomia

The Autonomic System Isn't a Switch (And Why That Matters)

The autonomic nervous system isn't an on/off switch. Learn why 'sympathetic dominance' is misleading and how specific pathways drive POTS symptoms.

Dr. Nathan Keiser
Neurology

The “Little Brain” That May Be Causing Your Dysautonomia

Cerebellar dysfunction causes dysautonomia and POTS. Learn how the cerebellum regulates autonomic reflexes and how eye movement testing reveals it.

Dr. Nathan Keiser
Neurology

The Vagus Nerve Isn’t What You Think

Vagus nerve stimulation for POTS misses the point. The vagus is mostly sensory, paired antagonism is a myth, and the real driver of dysautonomia differs.

Dr. Nathan Keiser
Dysautonomia

Why Standard Exercise Advice Fails POTS Patients

Exercise advice fails POTS patients because it ignores orthostatic blood flow. Deconditioning isn't the cause. Fix cerebral perfusion first.

Dr. Nathan Keiser
Vestibular

Why You Feel Better In The Car (And Worse When It Stops)

Mal de Debarquement Syndrome (MdDS) explains why you feel better in a moving car and worse when it stops. Learn about the sensory mismatch driving it.

Dr. Nathan Keiser
Neurology

Your Neck Might Be Part of the Problem

Neck stiffness with dysautonomia isn't random. Learn the neurological connection between your neck, vestibular system, and autonomic symptoms.

Dr. Nathan Keiser
Dysautonomia

You're Not Lazy: Your Brain Is Running on Empty

POTS fatigue and brain fog aren't laziness. Dr. Keiser explains why reduced cerebral blood flow starves your brain of fuel and what testing can reveal.

Dr. Nathan Keiser
Concussion

What Happens When a Concussion Doesn't Heal

Post-concussion symptoms that persist often involve disrupted cerebral blood flow and cerebellar dysfunction. Learn the brain mechanisms behind it.

Dr. Nathan Keiser
POTS

Why Heat Makes POTS Worse, and How to Build Your Tolerance Back

Why heat makes POTS worse: what heat does to brain blood flow and CO2, what the research shows, and how our team builds heat and sun tolerance.

Dr. Nathan Keiser
POTS

Air Hunger in POTS: Why You Can't Get a Full Breath

Air hunger in POTS feels like a breath that never fills. See what research shows about breathing on standing and how strong the evidence for breathing exercises is.

Dr. Nathan Keiser
POTS

What Triggers POTS Flare-Ups, and What to Do When One Hits

Heat, heavy meals, illness, standing still and the menstrual cycle can all set off a POTS flare. See what studies show, what to do and when to get help.

Dr. Nathan Keiser
POTS

POTS and EDS: Why They Show Up Together

POTS and EDS often show up together. See what studies show about the overlap, why the numbers vary, whether EDS causes POTS and how our team evaluates it.

Dr. Nathan Keiser
POTS

POTS Cardiologist or Neurologist? How to Choose Your Care

Is POTS neurological or cardiac? What each kind of POTS specialist tests and treats, the questions to ask, and what testing to expect.

Dr. Nathan Keiser
POTS

POTS Brain Fog: Causes and What Helps

POTS brain fog is slowed thinking and poor focus that often worsens on standing. See what studies show about brain blood flow and what our team tests.

Dr. Nathan Keiser
POTS

Hypovolemic POTS: Is Low Blood Volume the Whole Story?

Hypovolemic POTS is tied to low blood volume, yet salt and fluids often stall. Our team explains the symptoms, the tests and why volume isn't the whole story.

Dr. Nathan Keiser
POTS

Neuropathic POTS: What It Is, What Causes It and How It's Treated

In neuropathic POTS, nerves to the leg vessels are partly lost and blood pools when you stand. See what causes it, how it's tested and how our team treats it.

Dr. Nathan Keiser
POTS

ME/CFS vs POTS: How Do They Differ, and Can You Have Both?

POTS and ME/CFS can overlap, and a normal heart rate on a tilt can hide falling brain blood flow. Here's how our team separates them by mechanism.

Dr. Nathan Keiser
POTS

POTS Symptoms by Body System, With a Checklist

POTS symptoms by body system, from a racing heart to brain fog and nausea, with a printable checklist and how our team tests brain blood flow.

Dr. Nathan Keiser
POTS

POTS and Long COVID: How Dysautonomia Shows Up After COVID

How often POTS shows up in long COVID across 3 studies, why heart rate and dizziness change when you stand, and what our team measures first.

Dr. Nathan Keiser
POTS

Can a Concussion Cause POTS? Dysautonomia After Head Injury

Dysautonomia is increasingly recognized after concussion. See what studies show about POTS after a head injury and what a racing heart can tell you.

Dr. Nathan Keiser
POTS

Can Craniocervical Instability Cause POTS?

No controlled study has tested craniocervical instability as a cause of POTS. See what the imaging and surgery research shows and how our team reads the neck.

Dr. Nathan Keiser
POTS

POTS Diet and Nutrition: What the Research Can and Can't Tell You

A 2026 review concluded one standard POTS diet is unlikely to work. See the salt trial, what's unknown on caffeine, alcohol and supplements, and our approach.

Dr. Nathan Keiser
POTS

Intracranial Hypertension and POTS: Can You Have Both?

IIH and POTS can occur together. Learn what IIH is, how it's confirmed, which symptoms overlap with POTS, and why vision changes need prompt care.

Dr. Nathan Keiser
POTS

Does Red Light Therapy Help POTS?

Does red light therapy help POTS? What red light acts on, what the research shows so far, who it may help or hurt, and where it fits in our team's care.

Dr. Nathan Keiser
POTS

Can Mold, Lyme or CIRS Cause Dysautonomia?

Can mold, Lyme or CIRS cause POTS? What studies show on mold, CIRS testing and post-treatment Lyme, and what our team checks first.

Dr. Nathan Keiser
POTS

Hyperbaric Oxygen (HBOT) for POTS: Does It Help?

Our team found no trial of hyperbaric oxygen (HBOT) in POTS. See what HBOT changes in the blood, why blood flow matters, what trials show and the risks.

Dr. Nathan Keiser
POTS

Can Thoracic Outlet Syndrome Cause Dizziness or POTS?

What the research shows about thoracic outlet syndrome and dizziness, why no study links TOS to POTS yet, and how our team checks for compression.

Dr. Nathan Keiser
Neurology

Pupils Different Sizes After Head Injury: When to Go to the ER

When unequal pupils after a head injury mean calling 9-1-1 or going to the ER, how common a harmless difference is, and what concussion does to both pupils.

Dr. Nathan Keiser
POTS

Why Is POTS Worse in the Morning?

POTS is often worse in the morning. See what studies show about standing heart rate and test timing, plus our team's view on the neck and sleep posture.

Dr. Nathan Keiser
POTS

Can POTS Cause Seizures? Convulsive Syncope vs a Seizure

Seizure-like spells in POTS are often convulsive syncope: a faint with brief jerks. How to tell it from a seizure, what testing shows, and when to get help.

Dr. Nathan Keiser

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