POTS (Postural Orthostatic Tachycardia Syndrome) is a condition of the autonomic nervous system that affects heart rate regulation when changing position. Despite affecting an estimated 1–3 million Americans (Dysautonomia International) and approximately 500,000 people in the UK (POTS UK), it is frequently misdiagnosed or dismissed, with many patients waiting five to seven years for a diagnosis.
If you're experiencing dizziness, heart palpitations, extreme fatigue, or brain fog that worsens when you're upright, and you haven't yet been assessed for POTS, structured symptom tracking can meaningfully support that process.
What POTS is and how it's diagnosed
POTS is characterized by a heart rate increase of 30 beats per minute or more (40 bpm or more in those under 19) within 10 minutes of moving from lying to standing, without a significant drop in blood pressure. This is the diagnostic criterion established by the Heart Rhythm Society's 2015 Expert Consensus Statement.
Key symptoms include:
- Heart palpitations or awareness of a rapid heartbeat when upright
- Dizziness, lightheadedness, or pre-syncope (feeling close to fainting) when standing
- Extreme fatigue, particularly when standing or sitting upright for extended periods
- Brain fog: cognitive difficulty that worsens when upright
- Exercise intolerance
- Nausea
- Temperature regulation difficulties
POTS is diagnosed through a tilt table test or an active stand test. However, many people experience a significant delay before reaching this assessment, often because the relationship between posture and symptoms isn't recognized, or because symptoms are attributed to anxiety, deconditioning, or other conditions. POTS primarily affects women aged 15–50, though it can occur at any age and in people of any sex. Rates of POTS and POTS-like presentations increased following COVID-19, and POTS is now recognized as a component of Long COVID in some patients.
Why POTS is frequently missed
The orthostatic component of POTS (that symptoms worsen when upright) is often not the first thing patients report. Symptoms like fatigue, brain fog, and exercise intolerance can be attributed to anxiety, deconditioning, or depression, all of which delay recognition of the autonomic cause. The connection between standing and symptoms can feel obvious in retrospect but be genuinely invisible before someone knows to look for it.
What to track if you suspect POTS
The postural component
Note specifically whether your symptoms are worse when standing or sitting upright and improve when you lie down. This orthostatic pattern is the defining feature of POTS, and documenting it as explicitly as possible (with specific examples, dates, and circumstances) is the most important thing you can do to support an assessment.
Heart rate, if you have a monitor
If you have a heart rate monitor or smartwatch, record your resting heart rate when lying down and when standing after a few minutes. Note the date, time, and readings. A consistent difference of 30 bpm or more when moving from lying to standing is clinically significant and directly correlates with the diagnostic criterion.
Specific symptoms when upright
- Dizziness or lightheadedness
- Palpitations or awareness of heartbeat
- Nausea
- Brain fog
- Visual disturbances
- Shakiness or tremor
Known triggers
- Heat: hot environments or hot showers
- Large meals, particularly high-carbohydrate
- Prolonged standing or sitting upright
- Dehydration
- Time of day: symptoms often worsen in the morning
After diagnosis
POTS management is typically multimodal, combining increased fluid and salt intake, specific exercises (often starting in a reclined position), compression garments, and sometimes medication. Ongoing symptom tracking helps you and your clinical team identify which triggers affect you most and track the effect of any interventions.
Because POTS symptoms fluctuate significantly (often worsening with heat, hormonal changes, or illness), a record that reflects this variation is more informative than any single assessment.