A form of syncope that occurs upon assuming an upright position
Syncope is a temporary loss of consciousness due to the failure of the normal vasoconstrictive mechanisms to function, thus resulting in the inadequacy of blood flow to the brain. A syncope that is triggered by postural factor is referred to as postural syncope. Other examples of syncope are deglutition syncope (triggered by swallowing), tussive syncope (triggered by coughing), micturition syncope (triggered by the emptying of the bladder), and laughter-induced syncope (triggered by intense laughing). The postural syncope in comparison with the other forms of syncope (especially the laughter-induced syncope) is rather common in occurrence. It is said to be the commonest cause of recurrent syncope.1 According Vaddadi et al., a recurrent and unexplained postural syncope is often caused by circulatory control disorders and manifests in the following clinical phenotypes: vasovagal syncope, postural tachycardia (POTS), autonomic failure, initial orthostatic hypotention, and persistently low supine systolic blood pressure. Other disorders that can precipitate postural syncope are those relating to drugs, hypovolemia, and anemia. 1
1Gautam Vaddadi, Elisabeth Lambert, Susan J Corcoran and Murray D Esler. Postural syncope: mechanisms and management. Med J Aust 2007; 187 (5): 299-304.