Addison's Disease Support Group
Addison's disease (also known as chronic adrenal insufficiency, or hypocortisolism) is a rare endocrine disorder. It is estimated that it affects about 1 to 2 in 100,000 people. It occurs when the adrenal glands, seated above the kidneys, fail to produce enough of the hormone cortisol and, sometimes, the hormone aldosterone
As for the line on your nail; I have many of those. The lines are what initially had me asking my GP what they were. She wasn't sure and referred me to a dermotologist to see if they were related to skin issues. My dermotologist took many blood test because she thought they were related to my celiac disease or that I had hemochromotosis; which I did not. Finally I was referred to an endo who immediately tested me for Addison's. My endo was amazed that I was able to function at all because blood levels were the worst she had ever seen and I had the darkest tan and pattern tan areas she had ever seen. She had interns and residents and med. students in to see me because she said that they may never see a case of Addison's as clear cut as mine in their career. So, in my opinion the line on your fingernail is definitely related to Addison's. There are pictures online of a few other people with Addison's line.
Vanyel