Clinician handoff
Hypoperfusion
Designed for a 60-second scan in primary care. Use this to explain why this theory fits, what would weaken it, and which tests are most worth discussing.
Why this still fits
I want to evaluate whether reduced cerebral perfusion is driving my brain fog. The strongest clue is that the fog is worse upright and improves when I lie down or get circulation back.
What would weaken it
- -No upright worsening, no lightheadedness, and no sense that lying down reliably restores clarity.
- -Normal orthostatic evaluation combined with a story that fits sleep apnea, anxiety, or another cause better.
- -The fog is constant and unrelated to circulation, posture, or blood-flow stress.
Key points to communicate
- •I want to know whether this is true cerebral underperfusion or a nearby dysautonomia pattern like POTS.
- •Please separate blood-flow issues from anxiety, sleep loss, and simple fatigue.
- •If hypoperfusion is plausible, I want to know what objective measures would actually show it.
- •Could any of my current medications be contributing to orthostatic symptoms?
Bring this to the visit
- •Orthostatic vital signs if you have taken them: lying, sitting, and standing BP and HR.
- •A description of positional symptoms: does fog worsen when standing and improve lying down?
- •Fluid and salt intake estimate.
- •Medication list including antihypertensives, diuretics, and vasodilators.
Useful screening structure
- -Orthostatic vitals (lying, sitting, standing at 3 and 10 minutes).
- -NASA lean test (10 minutes standing against a wall) for more sensitive detection.
- -Transcranial Doppler if cerebral blood flow measurement is warranted.
Tests and measurements to discuss
Orthostatic vitals (lying-to-standing BP and HR)
What this helps clarify: Combined HR and BP measurements with position
Range context
Stable BP/HR
How to use the result
Save the result with date and symptoms from the same week.
Tilt-table test or NASA Lean Test if formal assessment needed
What this helps clarify: Gold standard for POTS and orthostatic intolerance
Range context
HR rise <30 bpm
How to use the result
Save the result with date and symptoms from the same week.
Active standing test (10-minute protocol)
What this helps clarify: Combined HR and BP measurements with position
Range context
Stable BP/HR
How to use the result
Save the result with date and symptoms from the same week.
CBC with ferritin (to rule out anemia as a contributor)
What this helps clarify: Iron storage marker that can affect energy, focus, and cognition.
Range context
40-100 ng/mL
How to use the result
Save the result with date and symptoms from the same week.
TSH (hypothyroidism can compound orthostatic symptoms)
What this helps clarify: This cluster is mainly there to rule out common medical overlaps that can mimic or amplify cognitive fog before settling on a single explanation.
BMP / electrolytes (dehydration and electrolyte imbalance)
Questions to ask directly
- •Is my fog from reduced cerebral blood flow, and how can we confirm this?
- •Should we evaluate for POTS, orthostatic hypotension, or subclavian steal?
- •Are my current medications reducing blood pressure or blood volume enough to cause symptoms?
- •Would salt loading, compression garments, or volume-expanding medications help?
Functional impact snapshot
- -Rate fog severity in different positions: lying flat, sitting, standing for 5+ minutes.
- -Track whether salt intake, hydration, or compression garments change cognitive function.
- -Note whether exercise tolerance and cognitive function improve or worsen together.
Escalate instead of self-managing if
- •Syncope or near-syncope with head injury risk.
- •New focal neurological deficits suggesting stroke or TIA.
- •Severe hypotension unresponsive to fluid loading requiring urgent evaluation.
Peer-reviewed references
- 1. Freeman R et al. Consensus statement on orthostatic hypotension, syncope, and POTS. Clin Auton Res. 2011;21(2):69-72 [DOI]
- 2. Sheldon RS et al. 2015 HRS Expert Consensus on POTS, Inappropriate Sinus Tachycardia, and Vasovagal Syncope. Heart Rhythm. 2015;12(6):e41-e63 [DOI]
- 3. Wells et al., JAHA, 2020 - Cerebral blood flow in POTS [DOI]