POTS brain fog is one of the most disabling symptoms reported by patients with postural orthostatic tachycardia syndrome — and it’s especially common in patients who also have Lyme disease. A study by Wells and colleagues confirms what many patients already know: POTS brain fog involves measurable impairments in short-term memory and alertness, not just subjective complaints.
For patients navigating both POTS and Lyme disease, understanding why brain fog occurs — and what drives it — is essential to getting the right care.
What Is POTS?
POTS is characterized by a substantial increase in heart rate — and sometimes a drop in blood pressure — when standing up. This can cause lightheadedness, heart palpitations, and in some cases, loss of consciousness.
POTS is a form of autonomic dysfunction — a disruption in the nervous system that controls heart rate, blood pressure, digestion, and temperature regulation. Many patients with Lyme disease develop POTS as part of their illness.
What the Research Shows About POTS Brain Fog
Wells and colleagues measured short-term memory and alertness in 11 POTS patients with brain fog using neurocognitive testing and compared them with 8 healthy controls.
They found that POTS patients demonstrated significantly longer response times on memory tasks and greater errors on attention-switching tasks — objective evidence that POTS brain fog reflects measurable cognitive impairment.
Importantly, while previous studies linked cognitive deficits in POTS to impaired cerebral blood flow, Wells and colleagues found that these deficits can occur even when cerebral blood flow appears normal. This suggests that POTS brain fog involves mechanisms beyond blood flow alone.
Why POTS Brain Fog Is Common in Lyme Disease
I have seen many patients with Lyme disease who suffer from both brain fog and POTS. The connection makes clinical sense — Lyme disease can trigger autonomic dysfunction, which disrupts the systems that regulate blood flow, heart rate, and nervous system signaling to the brain.
When the brain doesn’t receive stable blood flow and oxygen delivery — especially when standing or during exertion — cognitive function suffers. Patients describe slowed thinking, difficulty concentrating, word-finding problems, and mental fatigue that worsens with upright posture.
This pattern overlaps significantly with the broader picture of brain fog in Lyme disease, but POTS adds a postural component that makes symptoms predictably worse when standing, walking, or sitting upright for extended periods.
Symptoms of POTS Brain Fog
Patients with POTS brain fog commonly report:
- Slowed thinking that worsens when standing
- Difficulty sustaining attention or following conversations
- Short-term memory lapses
- Word-finding problems
- Mental fatigue disproportionate to activity
- Feeling “spaced out” or disconnected
- Improvement when lying down
The postural pattern is the key distinguishing feature — if brain fog consistently worsens when upright and improves when reclined, POTS should be on the differential.
Why Standard Tests Often Miss It
Routine blood work, brain imaging, and brief cognitive screening are frequently normal in patients with POTS brain fog. As Wells and colleagues demonstrated, even cerebral blood flow measurements may appear normal despite measurable cognitive impairment.
This disconnect — between objective impairment and normal test results — mirrors the broader challenge of medical dismissal in Lyme disease. Patients are told everything looks fine when it clearly isn’t.
Can POTS Brain Fog Improve?
Yes. Many patients experience improvement when the underlying autonomic dysfunction is addressed. Recovery strategies include treating the underlying Lyme disease and any co-infections, supporting autonomic regulation through hydration, salt intake, and compression garments, addressing sleep disruption and nervous system dysregulation, and gradual reconditioning when tolerated.
Improvement is often gradual and nonlinear — but when POTS is identified and managed, cognitive function frequently follows.
Frequently Asked Questions
Can POTS cause brain fog?
Yes. POTS brain fog involves measurable impairments in memory and attention. Research confirms these are objective cognitive deficits, not imagined symptoms.
Why is brain fog worse when I stand up?
POTS disrupts blood flow regulation when upright. The brain may not receive adequate perfusion, leading to slowed thinking, poor concentration, and mental fatigue.
Is POTS brain fog related to Lyme disease?
It can be. Lyme disease can trigger autonomic dysfunction including POTS. When both conditions are present, brain fog is often more severe.
Do normal brain scans rule out POTS brain fog?
No. Research shows cognitive impairment can occur even when cerebral blood flow and standard imaging appear normal.
Can POTS brain fog get better?
Yes. Many patients improve when autonomic dysfunction is addressed through treatment of underlying infections, lifestyle modifications, and supportive care.
References
- Wells R, Paterson F, Bacchi S, Page A, Baumert M, Lau DH. Brain fog in postural tachycardia syndrome: An objective cerebral blood flow and neurocognitive analysis. J Arrhythm. 2020;36(3):549-552.
My 59-year old daughter has had Lyme Disease for several years and appears to be suffering from psychological problems as a result of her chronic condition. Barbesia seems to be the culprit but since I live in Texas and she is near San Francisco, I do not see her often and can only make assumptions about her strange behavior. It is almost like a manic reaction to everyone in the family. In fact, her quick temper has literally alienated her from everyone. She has become a very angry person and having a normal relationship has become impossible for all her family. Breaks my heart. I suggested she see a therapist but was told her treatment is too expensive for that…what is a mother to do…..
It is a tough situation. I would love to be of assistance but I do not have a license in California.
Dear Dr Cameron;
We are in the Uk.
My son is 14. He has had brain fog symptoms every month or every other month for Around ten days at a time for a year now , since having an infection and high temperatures in June 2019. We are receiving a course of treatment consisting of natural supplements from the BCA but I wonder if we may be considered for ceftriaxone IV as he is suffering anxiety, depression, weight loss and losing too much of his young life. Thank you for your time.
I am sorry to hear your son is not well. I typically favor including an antibiotic in my treatment approach if I suspect Lyme disease. I typically start with oral even if there are neurologic and neuropsychiatric symptoms.
My 15 year old son started his decline in January 2019. He cycled between extreme mania and depression characterized by EXTREME brain fog. These cycles would last about 12 days each. There was no normal behavior in between. The school called me several times because he was so “foggy” they thought he would be a safety hazard. He couldn’t remember how to open a lunch pail. He had to be prompted on picking up a pencil. When he spoke, it sounded like he had a stroke. He could not find his words. He still became worse over time. His initial Lyme test was negative. His second was positive. We started him on several herbal meds and oral antibiotics. He still declined. During one manic session in November he had a very serious psychiatric break. Lost all touch with reality and ended up in a psychiatric hospital for two weeks. The day he came home we started IV rocephin 7 days a week. The antibiotics continued for 5 months. It is now August and he is finally being weaned off his oral antibiotics. His behavior has completely changed since the IV antibiotics. He is back to himself. There are so many things to this story I am leaving out. Some of the events that we experienced During his mania were just unbelievable. We thought our life, and his life was over. We have been seeing a wonderful specialist in Lyme disease. Our son would be a very interesting case study. We are waiting to see how his symptoms are when he is finally off ALL his meds. There is hope!
I am so happy that you found an answer for your son.
Please Put the boy on IV antibiotics. They saved my sons life. He was going through some serious psychological effects from Lyme disease.