POTS and Dizziness on Standing
Yes, Postural Orthostatic Tachycardia Syndrome (POTS) definitively causes dizziness on standing—this is one of its cardinal presenting symptoms and a key diagnostic feature. 1
Core Clinical Presentation
POTS patients present with severe orthostatic intolerance that includes light-headedness (dizziness) as a primary symptom, occurring within 10 minutes of standing. 1 The European Society of Cardiology guidelines explicitly list dizziness and light-headedness among the most frequent symptoms in their diagnostic criteria tables. 1
Characteristic Symptom Pattern
The dizziness in POTS has specific features that distinguish it from other causes:
- Timing: Symptoms develop upon standing and are relieved by sitting or lying down 1
- Exacerbating factors: Worse in the morning, with heat exposure, after meals, or following exertion 1
- Associated symptoms: Palpitations, tremor, generalized weakness, blurred vision, and fatigue accompany the dizziness 1
Recent clinical case series confirm that dizziness is the primary presenting complaint in POTS patients, with anxiety and headache as key associated features. 2
Pathophysiologic Mechanism
The dizziness results from cerebral hypoperfusion despite the absence of orthostatic hypotension. 3, 4 The underlying mechanisms include:
- Excessive venous pooling leading to reduced stroke volume and end-diastolic volume 5
- Impaired sympathetically mediated vasoconstriction 3
- Selective impairment of sympathetic venomotor function while arteriolar function remains intact 5
- Volume dysregulation and deconditioning 3
This creates a situation where patients experience symptoms of cerebral hypoperfusion and excessive sympathoexcitation simultaneously. 3
Diagnostic Distinction
Critical diagnostic point: POTS causes orthostatic dizziness WITHOUT orthostatic hypotension—this is what separates it from classical orthostatic hypotension. 2, 6 The diagnosis requires:
- Heart rate increase >30 bpm (or >120 bpm absolute) within 10 minutes of standing 1
- For patients aged 12-19 years, heart rate increase should be >40 bpm 1
- Absence of blood pressure drop meeting criteria for orthostatic hypotension 1
Common Pitfall to Avoid
Do not dismiss orthostatic dizziness simply because blood pressure measurements are normal on standing. 2 When patients present with orthostatic dizziness but lack orthostatic blood pressure fall, detailed autonomic function testing should be performed to evaluate for POTS. 2
Clinical Context
POTS predominantly affects young women and is frequently associated with recent infections, chronic fatigue syndrome, joint hypermobility syndrome, and deconditioning. 1 While syncope can occur, it is rare and usually results from vasovagal reflex activation rather than the POTS itself. 1
The functional disability can be substantial, with patients experiencing exercise intolerance, extreme fatigue, headache, and mental clouding in addition to the orthostatic dizziness. 3, 4