Most frequently occurs in otherwise young and healthy individuals, but may occur in older individuals with atypical prodromal symptoms. Often in the setting of an emotional or orthostatic stress such as painful stimuli, venipuncture, fear of bodily injury, prolonged standing, exertion, or heat exposure.
Patients typically describe a prodrome of nausea, pallor, and diaphoresis followed by a brief episode of syncope from either the sitting or standing position. Consciousness is restored with the supine position, but patients may feel fatigued for some time after the event.
Related topic: Drug-induced syncope
R55 – Syncope and collapse
398665005 – Vasovagal syncope