{"id":822,"date":"2026-10-21T06:44:15","date_gmt":"2026-10-21T06:44:15","guid":{"rendered":"https:\/\/brainfogremedy.com\/articles\/?p=822"},"modified":"2026-10-21T10:07:49","modified_gmt":"2026-10-21T10:07:49","slug":"pots-brain-fog","status":"publish","type":"post","link":"https:\/\/brainfogremedy.com\/articles\/pots-brain-fog\/","title":{"rendered":"POTS Brain Fog: What Patients Report and Studies Measured"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\"><strong>POTS brain fog is the forgetful, cloudy, slow thinking that 96 percent of 138 surveyed POTS patients reported in a 2013 study, and that 94 percent of 4,835 reported as difficulty concentrating in 2019. Small lab studies find it worst upright, yet it does not always clear lying down. 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small lab studies on posture with their numbers, the survey figures drawn as a chart, five r\/POTS threads from the past year with where they agree and part from the studies, and a checklist of what the studies asked about for an appointment.<\/p>\n\n\n\n<div class=\"msq\" id=\"ms-quiz\" data-slug=\"pots-brain-fog\" data-category=\"symptoms\" data-list=\"1\">\n<style>.msq,.msq-hook,.msq-box,.msq-end,.msq-tool{--msq-accent:#1F4E79;--msq-accent-text:#FFFFFF;--msq-line:#CBD8E6;--msq-warn:#B4531A;--msq-muted:#4A5560;--msq-tint:#EEF3F8;--msq-base:#FFFFFF}\n.msq{margin:1.25em 0 1.75em}\n.msq-hook{border-left:3px solid var(--msq-accent);padding:6px 14px;color:var(--msq-muted);font-size:.97em}\n.msq-box{background:var(--msq-tint);border:1px solid var(--msq-line);border-radius:12px;padding:0}\n.msq-box>summary{cursor:pointer;list-style:none;padding:14px 18px;font-weight:700;color:var(--msq-accent)}\n.msq-box>summary::-webkit-details-marker{display:none}\n.msq-box>summary::before{content:\"+\";display:inline-block;width:1.1em;font-weight:800}\n.msq-box[open]>summary::before{content:\"\\00d7\"}\n.msq-body{padding:2px 18px 18px}\n.msq-intro{margin:0 0 12px;font-size:.95em;color:var(--msq-muted)}\n.msq-list{margin:0;padding:0;list-style:none}\n.msq-q{margin:0 0 18px;padding:0}\n.msq-question{font-weight:700;margin:0 0 8px}\n.msq-options{display:flex;flex-direction:column;gap:8px}\n.msq-opt{text-align:left;background:var(--msq-base);border:1px solid var(--msq-line);border-radius:8px;padding:10px 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0 6px;font-size:1.15em}\n.msq-tool p{margin:0 0 10px}\n.msq-tool .msq-note{font-size:.85em;color:var(--msq-muted);margin:10px 0 0}\n.msq-check label{display:flex;gap:10px;align-items:flex-start;padding:9px 0;border-bottom:1px solid var(--msq-line);cursor:pointer;line-height:1.4}\n.msq-check label:last-of-type{border-bottom:0}\n.msq-check input{margin-top:5px;flex:0 0 auto;width:18px;height:18px;accent-color:var(--msq-accent)}\n.msq-check-count{font-weight:700;margin:10px 0 0}\n.msq-verdict-box{margin:12px 0 0;padding:10px 14px;border-radius:8px;background:var(--msq-base);border-left:3px solid var(--msq-warn)}\n.msq-verdict-box[hidden]{display:none}\n.msq-calc{display:grid;grid-template-columns:1fr 1fr;gap:10px 16px}\n.msq-calc label{display:flex;flex-direction:column;gap:4px;font-size:.92em}\n.msq-calc input,.msq-calc select{padding:8px 10px;border:1px solid var(--msq-muted);border-radius:8px;font:inherit;background:#fff}\n.msq-calc-out{grid-column:1 \/ -1;margin-top:6px;padding:12px 14px;background:var(--msq-base);border-radius:8px;border:1px solid var(--msq-line)}\n.msq-calc-out strong{font-size:1.15em}\n.msq-choose label{display:block;padding:9px 12px;margin:0 0 8px;background:var(--msq-base);border:1px solid var(--msq-line);border-radius:8px;cursor:pointer}\n.msq-choose input{margin-right:8px;accent-color:var(--msq-accent)}\n.msq-choice-result{margin-top:10px;padding:12px 14px;background:var(--msq-base);border-left:3px solid var(--msq-accent);border-radius:0 8px 8px 0}\n.msq-choice-result[hidden]{display:none}\n@media (max-width:600px){.msq-calc{grid-template-columns:1fr}}\nh2.wp-block-heading[id]{scroll-margin-top:24px}<\/style>\n<noscript><style>.msq-explain{display:block !important}<\/style><\/noscript>\n<details class=\"msq-box\">\n<summary>Think you already know this? Five questions, one minute.<\/summary>\n<div class=\"msq-body\">\n<p class=\"msq-intro\">Every answer is on this page. Answer from what you know now; the page fills in the rest.<\/p>\n<ol class=\"msq-list\">\n<li class=\"msq-q\" data-q=\"1\" data-answer=\"b\" data-title=\"What is POTS, and why does thinking get dragged into it?\" data-section=\"#what-is-pots-and-why-does-thinking-get-dragged-into-it\">\n<p class=\"msq-question\">1. What heart rate rise on standing does the 2015 Heart Rhythm Society statement require for an adult?<\/p>\n<div class=\"msq-options\" role=\"group\" aria-label=\"Question 1 options\"><button type=\"button\" class=\"msq-opt\" data-opt=\"a\">At least 10 beats per minute<\/button><button type=\"button\" class=\"msq-opt\" data-opt=\"b\">At least 30 beats per minute<\/button><button type=\"button\" class=\"msq-opt\" data-opt=\"c\">At least 60 beats per minute<\/button><\/div>\n<p class=\"msq-explain\" hidden><span class=\"msq-verdict\"><\/span>At least 30, or at least 40 at ages 12 to 19, with no orthostatic hypotension, per the <a href=\"https:\/\/lahrs.org\/guias_lahrs\/2015-heart-rhythm-society-expert-consensus-statement-on-the-diagnosis-and-treatment-of-postural-tachycardia-syndrome-inappropriate-sinus-tachycardia-and-vasovagal-syncope.pdf\" target=\"_blank\" rel=\"noopener\">2015 consensus statement<\/a>. <a class=\"msq-section\" href=\"#what-is-pots-and-why-does-thinking-get-dragged-into-it\">Read the section<\/a><\/p>\n<\/li>\n<li class=\"msq-q\" data-q=\"2\" data-answer=\"a\" data-title=\"How many people with POTS report brain fog?\" data-section=\"#how-many-people-with-pots-report-brain-fog\">\n<p class=\"msq-question\">2. In the 2013 survey of 138 people with POTS, what share experienced brain fog?<\/p>\n<div class=\"msq-options\" role=\"group\" aria-label=\"Question 2 options\"><button type=\"button\" class=\"msq-opt\" data-opt=\"a\">96 percent<\/button><button type=\"button\" class=\"msq-opt\" data-opt=\"b\">50 percent<\/button><button type=\"button\" class=\"msq-opt\" data-opt=\"c\">20 percent<\/button><\/div>\n<p class=\"msq-explain\" hidden><span class=\"msq-verdict\"><\/span>96 percent, and 67 percent had it daily, in the <a href=\"https:\/\/mail.dysautonomiainternational.org\/pdf\/BrainFog.pdf\" target=\"_blank\" rel=\"noopener\">Ross and colleagues survey<\/a>. <a class=\"msq-section\" href=\"#how-many-people-with-pots-report-brain-fog\">Read the section<\/a><\/p>\n<\/li>\n<li class=\"msq-q\" data-q=\"3\" data-answer=\"b\" data-title=\"Is POTS brain fog really worse standing up?\" data-section=\"#is-pots-brain-fog-really-worse-standing-up\">\n<p class=\"msq-question\">3. In the 2019 tilt study of eight people, when was working memory worse than in controls?<\/p>\n<div class=\"msq-options\" role=\"group\" aria-label=\"Question 3 options\"><button type=\"button\" class=\"msq-opt\" data-opt=\"a\">Only lying flat<\/button><button type=\"button\" class=\"msq-opt\" data-opt=\"b\">Only upright<\/button><button type=\"button\" class=\"msq-opt\" data-opt=\"c\">In both positions equally<\/button><\/div>\n<p class=\"msq-explain\" hidden><span class=\"msq-verdict\"><\/span>Only upright, at 60 degrees of tilt, per <a href=\"https:\/\/www.frontiersin.org\/journals\/neuroscience\/articles\/10.3389\/fnins.2019.00327\/full\" target=\"_blank\" rel=\"noopener\">Rodriguez and colleagues<\/a>, who called the study preliminary. <a class=\"msq-section\" href=\"#is-pots-brain-fog-really-worse-standing-up\">Read the section<\/a><\/p>\n<\/li>\n<li class=\"msq-q\" data-q=\"4\" data-answer=\"b\" data-title=\"Where do the accounts and the studies agree, and where do they part?\" data-section=\"#where-do-the-accounts-and-the-studies-agree-and-where-do-the\">\n<p class=\"msq-question\">4. What did the one study that measured brain blood flow in people with fog find while they were seated?<\/p>\n<div class=\"msq-options\" role=\"group\" aria-label=\"Question 4 options\"><button type=\"button\" class=\"msq-opt\" data-opt=\"a\">Reduced blood flow<\/button><button type=\"button\" class=\"msq-opt\" data-opt=\"b\">A normal blood flow response<\/button><button type=\"button\" class=\"msq-opt\" data-opt=\"c\">It did not measure blood flow<\/button><\/div>\n<p class=\"msq-explain\" hidden><span class=\"msq-verdict\"><\/span>A normal response to a visual task, beside slower test performance, per <a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC7280003\/\" target=\"_blank\" rel=\"noopener\">Wells and colleagues<\/a>. <a class=\"msq-section\" href=\"#where-do-the-accounts-and-the-studies-agree-and-where-do-the\">Read the section<\/a><\/p>\n<\/li>\n<li class=\"msq-q\" data-q=\"5\" data-answer=\"a\" data-title=\"What is worth describing at the appointment?\" data-section=\"#what-is-worth-describing-at-the-appointment\">\n<p class=\"msq-question\">5. What median delay from symptoms to diagnosis did the 2019 survey of 4,835 people report?<\/p>\n<div class=\"msq-options\" role=\"group\" aria-label=\"Question 5 options\"><button type=\"button\" class=\"msq-opt\" data-opt=\"a\">24 months<\/button><button type=\"button\" class=\"msq-opt\" data-opt=\"b\">2 weeks<\/button><button type=\"button\" class=\"msq-opt\" data-opt=\"c\">10 years<\/button><\/div>\n<p class=\"msq-explain\" hidden><span class=\"msq-verdict\"><\/span>A median of 24 months and a median of five doctors, per <a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC6790699\/\" target=\"_blank\" rel=\"noopener\">Shaw and colleagues<\/a>. <a class=\"msq-section\" href=\"#what-is-worth-describing-at-the-appointment\">Read the section<\/a><\/p>\n<\/li>\n<\/ol>\n<div class=\"msq-result\" hidden><\/div>\n<\/div>\n<\/details>\n<script>(function(){\n  if (window.__msqInit) { return; }\n  window.__msqInit = true;\n  var root = document.getElementById('ms-quiz');\n  if (!root) { return; }\n  var meta = { slug: root.getAttribute('data-slug'), category: root.getAttribute('data-category'),\n               list: root.getAttribute('data-list') || '1' };\n  function qs(el, s){ return el.querySelector(s); }\n  function qsa(el, s){ return Array.prototype.slice.call(el.querySelectorAll(s)); }\n  function track(name, params){\n    try { if (typeof gtag === 'function') { var p = params || {}; p.article = meta.slug; gtag('event', name, p); } } catch (e) {}\n  }\n  function jumpList(missed){\n    if (!missed.length) { return ''; }\n    return '<ul class=\"msq-jump\">' + missed.map(function(q){\n      return '<li><a href=\"' + q.getAttribute('data-section') + '\">' + q.getAttribute('data-title') + '<\/a><\/li>';\n    }).join('') + '<\/ul>';\n  }\n  function emailForm(){\n    return '<div class=\"msq-sub\"><p><strong>Get the next one.<\/strong> We publish new articles on ' + meta.category\n      + ' most weeks and recheck this page on Sundays. 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Calculators carry their own small script. *\/\n  function initTools(){\n    qsa(document, '.msq-check').forEach(function(box){\n      var key = 'msq-check-' + meta.slug + '-' + (box.getAttribute('data-id') || 'x');\n      var boxes = qsa(box, 'input[type=checkbox]'), count = qs(box, '.msq-check-count');\n      var yes = qs(box, '.msq-verdict-yes'), no = qs(box, '.msq-verdict-no');\n      var saved = {};\n      try { saved = JSON.parse(localStorage.getItem(key) || '{}'); } catch (e) {}\n      boxes.forEach(function(cb, i){ if (saved[i]) { cb.checked = true; } });\n      function refresh(){\n        var n = boxes.filter(function(cb){ return cb.checked; }).length, state = {};\n        boxes.forEach(function(cb, i){ if (cb.checked) { state[i] = 1; } });\n        try { localStorage.setItem(key, JSON.stringify(state)); } catch (e) {}\n        if (count) { count.textContent = n + ' of ' + boxes.length + (box.getAttribute('data-verb') || ' done'); }\n        if (yes && no) { yes.hidden = n === 0; no.hidden = n !== 0; }\n      }\n      boxes.forEach(function(cb){ cb.addEventListener('change', function(){ refresh(); track('tool_check', { tool: box.getAttribute('data-id') }); }); });\n      refresh();\n    });\n    qsa(document, '.msq-choose').forEach(function(box){\n      var results = qsa(box, '.msq-choice-result');\n      qsa(box, 'input[type=radio]').forEach(function(r){\n        r.addEventListener('change', function(){\n          results.forEach(function(el){ el.hidden = el.getAttribute('data-for') !== r.value; });\n          track('tool_choose', { tool: box.getAttribute('data-id'), choice: r.value });\n        });\n      });\n    });\n  }\n  \/\/ read progress: how far down the article the reader has scrolled, fired once per quarter\n  (function(){\n    var art = root.closest('article') || root.parentNode, fired = {};\n    function check(){\n      var top = art.getBoundingClientRect().top + window.pageYOffset, h = art.offsetHeight || 1;\n      var seen = (window.pageYOffset + window.innerHeight - top) \/ h * 100;\n      [25, 50, 75, 100].forEach(function(m){ if (seen >= m && !fired[m]) { fired[m] = true; track('read_progress', { percent: m }); } });\n    }\n    window.addEventListener('scroll', check, { passive: true }); window.addEventListener('load', check);\n  })();\n  if (document.readyState === 'loading') { document.addEventListener('DOMContentLoaded', initTools); } else { initTools(); }\n})();<\/script>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\">The clinic pages define POTS carefully and the charity pages list brain fog among its symptoms, but none of them put the patient surveys, the tilt table studies and the forum accounts side by side, which is where the interesting disagreements live. This page does that. It will not tell anyone whether their own fog is POTS. That takes a doctor with a heart rate monitor, and <a href=\"https:\/\/brainfogremedy.com\/articles\/brain-fog-causes\/\">the causes of brain fog a doctor checks first<\/a> make a long list.<\/p>\n\n\n\n<h2 id=\"what-is-pots-and-why-does-thinking-get-dragged-into-it\" class=\"wp-block-heading\">What is POTS, and why does thinking get dragged into it?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Postural tachycardia syndrome is a problem with being upright. The <a href=\"https:\/\/lahrs.org\/guias_lahrs\/2015-heart-rhythm-society-expert-consensus-statement-on-the-diagnosis-and-treatment-of-postural-tachycardia-syndrome-inappropriate-sinus-tachycardia-and-vasovagal-syncope.pdf\" target=\"_blank\" rel=\"noopener\">2015 Heart Rhythm Society consensus statement<\/a> defines it by three things: frequent symptoms that occur with standing, a heart rate increase of at least 30 beats per minute &#8220;when moving from a recumbent to a standing position&#8221; (at least 40 at ages 12 to 19), and &#8220;the absence of orthostatic hypotension&#8221;, meaning blood pressure does not fall the way it does in a faint. The statement puts prevalence at approximately 0.2 percent. Its list of standing symptoms is lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, exercise intolerance and fatigue. Thinking is not on that list. It turns up later, where the statement notes &#8220;cognitive dysfunction&#8221; with brain fog in its own quotation marks, and warns that two of the drugs used for POTS &#8220;can worsen brain fog  a condition that troubles many patients&#8221;.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The <a href=\"https:\/\/www.nhs.uk\/conditions\/postural-tachycardia-syndrome\/\" target=\"_blank\" rel=\"noopener\">NHS page on PoTS<\/a>, reviewed on 22 July 2026, is blunter. It lists &#8220;problems with thinking, memory and concentration (brain fog)&#8221; among the symptoms, says they &#8220;may be worse in the morning&#8221;, and names standing or sitting upright for long periods, heat, eating, too little fluid, alcohol and too much rest among the things that make them worse. The usual explanation for why thinking suffers is that less blood reaches the brain when a person with POTS is upright. As the studies below show, that explanation is half right, which is the most annoying kind of right.<\/p>\n\n\n\n<h2 id=\"how-many-people-with-pots-report-brain-fog\" class=\"wp-block-heading\">How many people with POTS report brain fog?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Two patient surveys have counted. They asked different questions of different groups, so the table keeps them apart.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Survey<\/th><th>Who answered<\/th><th>What they reported<\/th><\/tr><\/thead><tbody><tr><td><a href=\"https:\/\/mail.dysautonomiainternational.org\/pdf\/BrainFog.pdf\" target=\"_blank\" rel=\"noopener\">Ross and colleagues, Clinical Autonomic Research, 2013<\/a><\/td><td>138 people aged 14 to 29 with a POTS diagnosis, 88 percent female, recruited through POTS groups on social media<\/td><td>96 percent experienced brain fog and 67 percent had it daily. Top descriptors: forgetful (91 percent), difficulty thinking (89), difficulty focusing (88), cloudy (88), difficulty finding the right words (88). It impaired schoolwork for 86 percent<\/td><\/tr><tr><td><a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC6790699\/\" target=\"_blank\" rel=\"noopener\">Shaw and colleagues, Journal of Internal Medicine, 2019<\/a><\/td><td>4,835 people with a physician diagnosis of POTS, 94 percent female, median age at onset 17, surveyed online<\/td><td>Difficulty concentrating 94 percent, memory problems 87 percent, lightheadedness 99 percent. Median delay to diagnosis 24 months; 75 percent misdiagnosed first; 77 percent told the problem was psychiatric<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">Compiled from the two linked papers, read on 21 October 2026. Both are online surveys of people active in patient communities, so the percentages describe who answered, not everyone with POTS.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Those are not population rates: people with a mild version who never joined a patient group are missing from the denominator. Even so, when nine in ten respondents in two surveys six years apart name the same complaint, it is a real complaint. No focus supplement has ever published a number with a denominator that honest.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1600\" height=\"900\" src=\"https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/pots-brain-fog-chart.png\" alt=\"Bar chart of pots brain fog survey figures: 96 percent down to 87 percent across seven items.\" class=\"wp-image-824\" srcset=\"https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/pots-brain-fog-chart.png 1600w, https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/pots-brain-fog-chart-300x169.png 300w, https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/pots-brain-fog-chart-1024x576.png 1024w, https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/pots-brain-fog-chart-768x432.png 768w, https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/pots-brain-fog-chart-1536x864.png 1536w\" sizes=\"auto, (max-width: 1600px) 100vw, 1600px\" \/><figcaption class=\"wp-element-caption\">Share of respondents agreeing with each complaint in two online patient surveys. Both recruited through patient communities, so these describe who answered, not everyone with POTS.<\/figcaption><\/figure>\n\n\n\n<h2 id=\"is-pots-brain-fog-really-worse-standing-up\" class=\"wp-block-heading\">Is POTS brain fog really worse standing up?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Mostly, with a catch. In the <a href=\"https:\/\/mail.dysautonomiainternational.org\/pdf\/BrainFog.pdf\" target=\"_blank\" rel=\"noopener\">2013 survey<\/a>, 87 percent named prolonged standing as a trigger and 81 percent said lying down helped. The catch is in the same paper: the authors had assumed the fog was driven by posture, and found instead that &#8220;subjects did not agree that lying down relieved brain fog and felt that brain fog could be triggered in the supine position&#8221;. Physical fatigue set it off while lying down for 72 percent and lack of sleep for 70. Their conclusion: other factors besides standing upright may also cause this symptoms to continue.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1376\" height=\"768\" src=\"https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/man-leaning-desk-standing-pots-brain-fog.jpg\" alt=\"A man leans on his desk, pausing during a moment of pots brain fog in his office.\" class=\"wp-image-820\" srcset=\"https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/man-leaning-desk-standing-pots-brain-fog.jpg 1376w, https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/man-leaning-desk-standing-pots-brain-fog-300x167.jpg 300w, https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/man-leaning-desk-standing-pots-brain-fog-1024x572.jpg 1024w, https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/man-leaning-desk-standing-pots-brain-fog-768x429.jpg 768w\" sizes=\"auto, (max-width: 1376px) 100vw, 1376px\" \/><figcaption class=\"wp-element-caption\">Standing upright can trigger or worsen cognitive difficulties for many patients.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The laboratory studies are small, and three of them point in slightly different directions.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>Study<\/th><th>Who and how<\/th><th>What it found<\/th><\/tr><\/thead><tbody>\n<tr><td><a href=\"https:\/\/pure.psu.edu\/en\/publications\/cognitive-dysfunction-in-postural-tachycardia-syndrome\/\" target=\"_blank\" rel=\"noopener\">Arnold and colleagues, Clinical Science, 2015<\/a><\/td><td>28 women with POTS and 24 controls, tested semi recumbent, with orthostatic stress minimised<\/td><td>Selective attention and processing speed lower in the POTS group; sustained attention, memory and verbal fluency not significantly different. A deficit without standing<\/td><\/tr>\n<tr><td><a href=\"https:\/\/www.frontiersin.org\/journals\/neuroscience\/articles\/10.3389\/fnins.2019.00327\/full\" target=\"_blank\" rel=\"noopener\">Rodriguez and colleagues, Frontiers in Neuroscience, 2019<\/a><\/td><td>8 people with neuropathic POTS and 8 controls, tested flat and at 60 degrees tilt, before and 20 minutes after 500 ml of water drunk within 5 minutes<\/td><td>Working memory worse than controls only upright. After the water the heart rate rise on tilt fell from 41.5 to 24.9 beats per minute and working memory improved. The authors call it preliminary: no randomisation, no sham<\/td><\/tr>\n<tr><td><a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC7280003\/\" target=\"_blank\" rel=\"noopener\">Wells and colleagues, Journal of Arrhythmia, 2020<\/a><\/td><td>11 people with POTS, all reporting brain fog, and 8 controls, tested seated with brain artery blood flow measured during a visual task<\/td><td>Slower on a delayed matching task, 3,630 against 2,482 milliseconds, and fewer attention switching responses right, 156 against 159. Blood flow response normal: impaired memory and alertness &#8220;despite normal CBF&#8221;<\/td><\/tr>\n<\/tbody><\/table><figcaption class=\"wp-block-table__caption\">Compiled from the three linked papers, read on 21 October 2026. The samples are 8 to 28 people, so each result is a group average that may not hold for any one person.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Put together: posture matters, the fog can outlast the posture, a test can show a difference while the blood flow reading looks ordinary, and a glass of water changed the numbers in eight people once. Anyone selling a six question quiz that explains all that is selling the quiz, not the explanation.<\/p>\n\n\n\n<h2 id=\"what-do-people-with-pots-say-the-fog-feels-like\" class=\"wp-block-heading\">What do people with POTS say the fog feels like?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Five threads on the r\/POTS forum from the past year, with 85 comments under them, were read for this page on 21 October 2026. What follows is what people report, paraphrased, dated and linked. It is testimony, not evidence.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In <a href=\"https:\/\/www.reddit.com\/r\/POTS\/comments\/1ou2o2b\/is_your_brain_fog_more_of_a_physical_feeling_or\/\" target=\"_blank\" rel=\"noopener\">a thread from November 2025<\/a> someone asked whether other people&#8217;s fog was a physical feeling or foggy thinking. Of the 25 replies read, most said both: a head full of cotton wool, air like thick soup, a bruised brain, and on the thinking side, losing a word mid sentence, calling a dog a chicken while knowing it was a dog, and reactions slow enough that other people noticed. Two mentioned tunnel vision while driving; one had stopped driving over it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/www.reddit.com\/r\/POTS\/comments\/1p1e1je\/anyone_feel_better_and_have_less_brain_fog_laying\/\" target=\"_blank\" rel=\"noopener\">A thread the same month<\/a> asked whether anyone else had less fog lying down than sitting at a desk. The replies were almost amused: that is the P and the O in the name, one wrote, and another pointed out that upright includes sitting. In <a href=\"https:\/\/www.reddit.com\/r\/POTS\/comments\/1u3rwpk\/concussed_feeling_and_cognitive_issues_after\/\" target=\"_blank\" rel=\"noopener\">June 2026<\/a>, someone mostly bed bound described a concussed feeling after sitting up, worse as their medication wore off and easing a little lying flat; one reply said that was simply brain fog, the poster said it felt different, like being hit.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/www.reddit.com\/r\/POTS\/comments\/1umciup\/the_brain_fog_is_so_intense_i_dont_enjoy_anything\/\" target=\"_blank\" rel=\"noopener\">The most upvoted thread, from July 2026<\/a>, came from someone who could not absorb a page of a book or remember the day by evening. Several replies had lost reading too; one kept it by playing the audiobook while holding the paper copy. One person reported their fog lifting within a week of starting a prescription medicine; another said their own doctor had warned them off daily use of the same drug. The thread never settled it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And in <a href=\"https:\/\/www.reddit.com\/r\/POTS\/comments\/1wv53ct\/struggle_with_brain_fog_and_memory_feels_like_im\/\" target=\"_blank\" rel=\"noopener\">October 2026<\/a>, a 22 year old student wrote that they could not remember what they ate the day before without asking someone. The replies included a doctoral candidate who had forgotten their own computer password, someone who forgot the PIN they used daily, a UK student&#8217;s list of university accommodations, and two people whose fog turned out to involve a second diagnosis, a sleep disorder in one case. Several replies recommended supplements. This site does not, and nothing on this page tested one.<\/p>\n\n\n\n<h2 id=\"where-do-the-accounts-and-the-studies-agree-and-where-do-the\" class=\"wp-block-heading\">Where do the accounts and the studies agree, and where do they part?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">They agree more than either side might expect. Posture: 87 percent in the <a href=\"https:\/\/mail.dysautonomiainternational.org\/pdf\/BrainFog.pdf\" target=\"_blank\" rel=\"noopener\">2013 survey<\/a> named standing as a trigger, the 2019 tilt study found the working memory deficit only upright, and a whole thread treated lying down helping as too obvious to ask. Words: 88 percent in that survey agreed with difficulty finding the right words, and the forum gave it the dog and the chicken. Memory: 87 percent in the <a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC6790699\/\" target=\"_blank\" rel=\"noopener\">2019 survey<\/a> reported memory problems, and the forum supplied the forgotten PIN.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They part in four places. The forum attributes the fog to blood flow with confidence; the one study that measured blood flow in people with fog found it normal while seated. The studies measure minutes on a tilt table; the accounts describe years, dropped courses and careers. The physical sensation, the cotton wool and the bruise, appears in no study here, which measured reaction times. And the forum reaches for supplements and medication swaps that no study here tested against fog. None of that makes the accounts wrong. It makes them a list of things the studies have not yet asked.<\/p>\n\n\n\n<h2 id=\"does-pots-after-covid-bring-the-same-fog\" class=\"wp-block-heading\">Does POTS after COVID bring the same fog?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Possibly, and nobody has checked properly. <a href=\"https:\/\/link.springer.com\/article\/10.1007\/s12026-021-09185-5\" target=\"_blank\" rel=\"noopener\">Blitshteyn and Whitelaw<\/a> published a case series of 20 patients with POTS and other autonomic disorders after COVID-19 infection in Immunologic Research in 2021, and the <a href=\"https:\/\/www.nature.com\/articles\/s44161-022-00177-8\" target=\"_blank\" rel=\"noopener\">Cedars-Sinai analysis of 284,592 vaccinated people<\/a> in Nature Cardiovascular Research in 2022 found the odds of a new POTS diagnosis higher in the 90 days after a COVID-19 infection than after vaccination, which the authors describe as an association, not a cause. None of the cognition studies in the table above enrolled people whose POTS began after COVID. Whether the fog of post COVID POTS is the same fog, measured the same way, is an open question, and <a href=\"https:\/\/brainfogremedy.com\/articles\/covid-brain-fog\/\">what the evidence says about COVID brain fog on its own<\/a> is a separate and larger literature.<\/p>\n\n\n\n<h2 id=\"what-is-worth-describing-at-the-appointment\" class=\"wp-block-heading\">What is worth describing at the appointment?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The <a href=\"https:\/\/www.nhs.uk\/conditions\/postural-tachycardia-syndrome\/\" target=\"_blank\" rel=\"noopener\">NHS<\/a> says a GP may check blood pressure and heart rate before and after standing, repeated several times as an active stand test, with blood tests and an ECG to rule out other causes and a tilt table test at a specialist clinic if needed. The <a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC6790699\/\" target=\"_blank\" rel=\"noopener\">2019 survey<\/a> explains why the description matters: a median of 24 months to diagnosis, a median of five doctors, and 77 percent told the problem was psychiatric along the way. &#8220;I feel stupid&#8221; gets a different appointment from &#8220;it starts about ten minutes after I stand and eases when I lie down&#8221;. <a href=\"https:\/\/brainfogremedy.com\/articles\/mental-fogginess-meaning\/\">How to describe brain fog so a doctor takes it seriously<\/a> covers the general case; the checklist below covers what the POTS studies asked about: timing against posture, time of day (25 percent in the 2013 survey had it worst in the morning, 36 percent saw no pattern), sleep, heat, meals, and what it stops you doing. It records nothing and decides nothing.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1376\" height=\"768\" src=\"https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/symptom-journal-tracking-pots-brain-fog.jpg\" alt=\"An open journal on a bedside table helps track symptoms related to pots brain fog.\" class=\"wp-image-821\" srcset=\"https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/symptom-journal-tracking-pots-brain-fog.jpg 1376w, https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/symptom-journal-tracking-pots-brain-fog-300x167.jpg 300w, https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/symptom-journal-tracking-pots-brain-fog-1024x572.jpg 1024w, https:\/\/brainfogremedy.com\/articles\/wp-content\/uploads\/2026\/10\/symptom-journal-tracking-pots-brain-fog-768x429.jpg 768w\" sizes=\"auto, (max-width: 1376px) 100vw, 1376px\" \/><figcaption class=\"wp-block-image__caption\">The studies asked when the fog appears and what eases it. A note of both is what an appointment can use.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Two things sit outside any checklist. Confusion that is new or sudden, fainting that causes injury, chest pain or breathlessness with a racing heart are reasons to seek medical help now, not to keep a diary. And nothing here is a reason to delay seeing a doctor about a fog that worries you, whatever a forum or this page says.<\/p>\n\n\n\n<div class=\"msq-tool msq-check\" data-id=\"pots-appointment-notes\" data-verb=\" noted\">\n<h3>What the POTS studies asked about, for the appointment<\/h3>\n<p>Seven things worth being able to describe. Tick the ones you can already answer for yourself.<\/p>\n<label><input type=\"checkbox\">When the fog starts relative to standing or sitting up, and roughly how long after<\/label>\n<label><input type=\"checkbox\">Whether lying down changes it, and how long that takes<\/label>\n<label><input type=\"checkbox\">The time of day it is worst, or that there is no pattern<\/label>\n<label><input type=\"checkbox\">How the night&#8217;s sleep was before a bad day<\/label>\n<label><input type=\"checkbox\">Whether heat, a large meal or a hot shower came first<\/label>\n<label><input type=\"checkbox\">What it stopped you doing that day: reading, work, a conversation<\/label>\n<label><input type=\"checkbox\">Any timing that lines up with a medicine, for the doctor to interpret<\/label>\n<p class=\"msq-check-count\"><\/p>\n<p class=\"msq-note\">Ticks stay on this device. This list records nothing, scores nothing and does not decide what is causing anything; that is the appointment&#8217;s job.<\/p>\n<\/div>\n\n\n\n<h2 id=\"frequently-asked-questions\" class=\"wp-block-heading\">Frequently asked questions<\/h2>\n\n\n<div id=\"rank-math-faq\" class=\"rank-math-block\">\n<div class=\"rank-math-list \">\n<div id=\"faq-q-1\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \">Is brain fog part of the official POTS criteria?<\/h3>\n<div class=\"rank-math-answer \">\n\n<p>No. The 2015 Heart Rhythm Society criteria are symptoms on standing, a heart rate rise of 30 beats per minute or more (40 at ages 12 to 19) and no orthostatic hypotension. The statement mentions brain fog as something seen in patients, not as a diagnostic requirement.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-q-2\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \">Does drinking water fix POTS brain fog?<\/h3>\n<div class=\"rank-math-answer \">\n\n<p>In one 2019 study of eight people, working memory upright improved 20 minutes after 500 ml of water, and the authors called the result preliminary. The NHS gives drinking enough fluids as general advice. How much is right for any one person is a question for their own clinician.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-q-3\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \">Why is POTS brain fog worse in the morning for some people?<\/h3>\n<div class=\"rank-math-answer \">\n\n<p>The NHS says PoTS symptoms may be worse in the morning, and in the 2013 survey 25 percent said the fog was most severe then while 36 percent saw no pattern. No study on this page explains the morning effect.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-q-4\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \">Can a cognitive test prove someone has POTS brain fog?<\/h3>\n<div class=\"rank-math-answer \">\n\n<p>No. The studies here found group differences in samples of 8 to 28 people on tasks like delayed matching and working memory. They did not produce a test that identifies the fog in an individual, and none is in use for that purpose.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-q-5\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \">Does POTS brain fog get better over time?<\/h3>\n<div class=\"rank-math-answer \">\n\n<p>Nobody has measured it over time. Both surveys were snapshots, and the lab studies tested people on a single day. Forum accounts went both ways, from fog that lifted to fog that had lasted years, so the honest answer is unknown.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-q-6\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \">Is POTS brain fog the same as long COVID brain fog?<\/h3>\n<div class=\"rank-math-answer \">\n\n<p>The two overlap, because POTS can follow COVID-19 infection, but no study has compared the fog in the two groups. The cognition studies cited here were done before the pandemic on people whose POTS had other beginnings.<\/p>\n\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n<div class=\"msq-end\" id=\"ms-quiz-end\">\n<p><strong>Finished the page?<\/strong> The same five questions from the top, to see what stuck.<\/p>\n<button type=\"button\" class=\"msq-btn msq-start-test\">Test Your Understanding of This Article<\/button>\n<div class=\"msq-mount\"><\/div>\n<\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\"><em>This article is general information, not medical advice, and is not a substitute for care from a qualified healthcare professional. Speak to your doctor about your own situation.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>What two patient surveys of 138 and 4,835 people counted, what four small lab studies found about posture, and what five r\/POTS threads from the past year say the fog feels like, with where they agree and where they part.<\/p>\n","protected":false},"author":1,"featured_media":819,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","rank_math_title":"POTS Brain Fog: What Patients Report and Studies Measured","rank_math_description":"POTS brain fog was reported by 96 percent of 138 surveyed patients and 94 percent of 4,835. Small studies find it worst upright. Five threads describe it.","rank_math_focus_keyword":"pots brain fog","rank_math_canonical_url":"","rank_math_breadcrumb_title":"","rank_math_facebook_title":"","rank_math_facebook_description":"","rank_math_facebook_image":"","rank_math_twitter_title":"","rank_math_twitter_description":"","rank_math_twitter_image":"","rank_math_pillar_content":"","rank_math_robots":[],"rank_math_advanced_robots":[]},"categories":[4],"tags":[],"class_list":["post-822","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-symptoms"],"_links":{"self":[{"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/posts\/822","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/comments?post=822"}],"version-history":[{"count":6,"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/posts\/822\/revisions"}],"predecessor-version":[{"id":832,"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/posts\/822\/revisions\/832"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/media\/819"}],"wp:attachment":[{"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/media?parent=822"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/categories?post=822"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/brainfogremedy.com\/articles\/wp-json\/wp\/v2\/tags?post=822"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}