I am suddenly transposing letters when I type and having to constanly correct my mistakes. Why is this happening all of a sudden
Anything of a short duration cannot be termed as a disease as such. If it is of serious difference, then it should be looked into. Also, WRT typing, it is difficult to term it as Dyslexia. Hence, I would advise you not to worry about it as of now and then consider consulting a Neurologist if you face more of problems.