Mine are defintely something wrong with my heart or a stroke and anything to do with my pancreas. I had pancreatitis once and I did not realize that it can be life threatening and it was something I just randomly got.

Other than that I dont tend to fear cancer that much unless I think I feel a lump, I used to fear MS because of flashing lights in my eyes and major brisk reflexes but since I still have all that and I am still alive I have not worried so much