Table 1.

Defining characteristics of orthostatic hypotension (OH) variants, vasovagal syncope (VVS), and postural tachycardia syndrome (POTS).

Disorder	Hemodynamic Change(s) with Standing
	Direction and Magnitude	Time of Onset	Duration
Classical OH	↓ SBP ≥20 mmHg or ↓ DBP ≥10 mmHg	≤3 min	Sustained
Classical OH + Supine HTN	↓ SBP/DBP ≥30/15 mmHg	≤3 min	Sustained
Delayed OH	↓ SBP ≥20 mmHg or ↓ DBP ≥10 mmHg	≥3 min	Sustained
Initial OH	↓ SBP ≥40 mmHg and/or ↓ DBP ≥20 mmHg	≤15 s	Transient (resolves within 45–60 s of onset)
VVS	Preserved BP/HR until syncope prodrome Time of faint: ↓ BP and ↓ HR	Variable	Until faint
POTS	↑ HR ≥30 mmHg No OH	≤10 min	Sustained

Abbreviations: SBP, systolic blood pressure; DBP, diastolic blood pressure; HR, heart rate; HTN, hypertension; HR, heart rate