TL;DR: Brain fog and overstimulation are two of the most disruptive and least-talked-about parts of POTS. The fog (trouble thinking, forgetfulness, losing words) is linked to reduced blood flow to the brain and to fatigue. Overstimulation, where busy, bright or noisy places quickly become overwhelming, is also common. Neither means you are weak or "losing it." Lightening your mental load, managing the underlying POTS basics, reducing sensory input, and resting all help.
People with POTS often say the brain fog scares them more than the heart symptoms, and that nobody warned them how overwhelming a supermarket could feel. Both are real and recognised. Here is what is going on and what helps, based on Dysautonomia International and standard POTS guidance.
What POTS brain fog feels like
POTS brain fog shows up as trouble concentrating, forgetfulness, losing words mid-sentence, slow or fuzzy thinking, and difficulty following conversations. It can be frightening, especially at work or in social situations, but it is a known part of POTS, not a sign your mind is failing.
Why it happens
The leading explanation links the fog to the same problem behind the rest of POTS: when blood pools and does not reach the brain as well, especially when upright, thinking gets harder. Add the deep fatigue and disrupted sleep that come with POTS, and the fog thickens. It often gets worse on standing and better when lying down, which is a clue to its cause.
Overstimulation and sensory overload
Many people with POTS find busy, bright, loud environments, like shops, crowds or parties, quickly overwhelming. Some also experience derealisation, a strange feeling of being detached or that the world is not quite real. These can be exhausting and even trigger or worsen other symptoms. They are part of how a sensitised, under-resourced nervous system responds to too much input.
What helps the fog
Treating the underlying POTS often helps the fog, so the basics matter: fluids, salt, compression and pacing. Beyond that, lightening your mental load works: write things down, use lists and reminders, do thinking-heavy tasks when you are most upright and rested, and tackle one thing at a time. Lying down or getting your feet up can sometimes clear the fog enough to think.
What helps with overstimulation
Reducing input is the goal. Go to shops at quieter times, use sunglasses or noise-reducing earplugs, take breaks, and plan a calm recovery afterwards. A quiet, dim, soft space to decompress is not a luxury after overload, it is a reset. Many people find a cooling gel mask or a dark, quiet room helps them come back down, and some reach for a weighted sleep mask to block out light and gentle pressure to settle when everything feels like too much.
Be gentle with yourself
The fog and overwhelm can make you feel embarrassed or scared. Treat a foggy, overstimulated day like a high-symptom day: lower the bar, skip what can wait, and forgive yourself. You are managing something genuinely hard. On those days, our POTS comfort collection is here to make rest easier. Comfort, never a cure.
Frequently asked questions
Does POTS cause brain fog?
Yes. Brain fog is a common, recognised symptom of POTS, linked to reduced blood flow to the brain and to fatigue, and it often worsens when upright.
Why do I feel overstimulated with POTS?
Busy, bright or loud environments overwhelm an already-strained nervous system, which is common in POTS and can trigger or worsen other symptoms.
What is derealisation in POTS?
A feeling of detachment or that the world is not quite real, which some people with POTS experience, often alongside fog and overstimulation. It can be unsettling but is recognised.
How do I clear POTS brain fog?
Treating the underlying POTS helps, along with lightening your mental load, resting, and sometimes lying down or elevating your feet to improve blood flow to the brain.
How do I cope with sensory overload from POTS?
Reduce input with quieter times, sunglasses or earplugs, take breaks, and plan a calm, dim recovery space afterwards.
This article is general information, not medical advice, and is not intended to diagnose, treat, cure, or prevent any condition. If you are worried about memory or thinking, talk to your doctor. Sources: Dysautonomia International, Cleveland Clinic, Johns Hopkins Medicine.
Written by the Soft Days team, a small brand built by a family that lives with chronic illness. Last updated June 2026.