There is a scary, scary word in the medical community.
It's called idiopathic and it's a term that patients never want to hear, and one that doctors never want to mutter. Idiopathic is the term assigned to a pathology when the cause is unknown.
Yep, you've got ____ and nobody knows why.
The major problem with idiopathic pathologies is that it makes treating and preventing the condition extremely tricky. If treating the root cause is the best form of treatment, what do you do when the root cause is unknown? It also makes establishing risk factors for certain conditions harder. Which puts everybody at risk... oh joy.
Another problem with idiopathic pathologies is the worry that if they are of unknown origin, that they will forever be of unknown origin. Perhaps this is a bit pessimistic, but I sometimes doubt that even with scientists researching all around the world at a constant rate, that we'll ever be able to explain the cause of every health condition out there. The body is just too complex and we are all so individual that tracking down the root cause of everything can be tricky (especially due to the prevalence of autoimmune diseases, but that's another story for another blog post). It is possible, however, that an individual cause can be identified for one individual with the disease. For example, we don't know what causes X globally, but it seems that in Sally's case, Y was the trigger.