There are several varieties: that called Addison's disease, that due to uterine disease, etc.
"Anomalies and Curiosities of Medicine" by George M. Gould
Addison's Disease always ends suddenly.
"Essays In Pastoral Medicine" by Austin ÓMalley
Addison's Disease and Cushing's Syndrome.
You see, 2 years ago Nathan was diagnosed with Addison's Disease and Diabetes --a combination that can be deadly if his blood sugar levels aren't constantly monitored.
Addison seems to be giving in to her attraction to Pete, Violet is actively trying to befriend her ex-lover Alan, and Naomi's teenage daughter visits Addison in the clinic for possible STD's (sexually transmitted disease).