I believe the most common cause is infectious, followed by autoimmune.
Here is a link:
http://en.wikipedia.org/wiki/Pericardial_effusion
One of my son's teachers in high school, continued exercise while he had a virus and developed this severely, and almost died as a result. Otherwise healthy, and only 42 yrs old.
There are mild forms and acute forms. That is basically all I know about it, as one really needs a doctor to carefully follow you if you show effusion tendencies.
__________________
All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
************************************
.
Weezie looking at petunias 8.25.2017
****************************
These forums are for mutual support and information sharing only. The forums are not a substitute for medical advice, diagnosis or treatment provided by a qualified health care provider. Always consult your doctor before trying anything you read here.