A family member was diagnosed with "capillary leak syndrome" thru mayo clinic- what is that? how does one get it ? can they do much to help?

Genetic, very rare.: Clarkson's disease is what it is called. It is a very rare genetic mutation. It causes episodes of fluid leaking out of the blood vessels into the tissue. This can lead to low blood pressure, passing out or damage to organs from the low bp, even death. Need to see a specialist in this! https://en.Wikipedia.Org/wiki/capillary_leak_syndrome http://www.Ncbi.Nlm.Nih.Gov/pmc/articles/pmc2947962/.