When I turned 30, I got very sick. I could not work. I went from 160lbs., to 110lbs. I started going to doctors 2-3 times per week, every week. Yet no one could find the problem. I kept offering out my family history, but that was always dismissed. After about 1.5 years of this, I complained of a pain just below my rib cage. I was told it was liver and spleen. I was immediately sent to a specialist. He studied my history for quite a while, and after two visits, learned it was sarcoidosis.
Sadly, over the years it has caused extensive damage to my body, including: liver, spleen, lungs, heart, kidneys, skin, bones, joints, tendons, brain, eyes, etc. Those I what I recall at the moment. They are in no particular order.
This has NOT been a fun road to travel. I hope they can find a cure that can help all afflicted.