Hi Mathias,
I have been having similar symptoms for the last few months. In particular, I also have the thinner hands with visible veins (my veins have *never* been visible; phlebotomists have always had to work very hard to find one and draw blood). I am in addition having shortness of breath with exertion and during sleep; my FVC came out to 69%, so I am very afraid this may be ALS. Just thought I'd let you know you're not alone in the constant and life-ruining anxiety.
Best of luck,
S