Editing Orthostatic intolerance (section)

==Causes==
Symptoms of OI are triggered by:
* An upright posture for long periods (e.g. standing in line, standing in a shower, or even sitting at a desk)
* A warm environment (e.g. hot summer weather, a hot crowded room, a hot shower or bath, after exercise)
* Emotionally stressful events (seeing blood or gory scenes, being scared or anxious)
* Return from an extended stay in space, when the body is not yet readapted to gravity<ref name=Joyner>{{cite journal |last1=Joyner |first1=Michael J. |last2=Masuki |first2=Shizue |title=POTS versus deconditioning: the same or different? |journal=Clinical Autonomic Research |date=December 2008 |volume=18 |issue=6 |pages=300–307 |doi=10.1007/s10286-008-0487-7 |pmid=18704621 |pmc=3770293 }}</ref>
* Extended [[bedrest]]<ref name=Joyner />
* Inadequate [[fluid intake|fluid]] and [[Health effects of salt|salt intake]]<ref name="generalinfo"/>
* Concussion<ref>{{Cite journal |last=Pertab |first=Jon L. |last2=Merkley |first2=Tricia L. |last3=Cramond |first3=Alex J. |last4=Cramond |first4=Kelly |last5=Paxton |first5=Holly |last6=Wu |first6=Trevor |date=2018 |title=Concussion and the autonomic nervous system: An introduction to the field and the results of a systematic review |url=https://pubmed.ncbi.nlm.nih.gov/29660949/ |journal=NeuroRehabilitation |volume=42 |issue=4 |pages=397–427 |doi=10.3233/NRE-172298 |issn=1878-6448 |pmc=6027940 |pmid=29660949}}</ref>