What Causes Discoloration And Sensitivity In Toes?

Hi ...I have been happy to say and thankful to God for my good health at age 75 ! Today the doctor suspects I have Reynauds due to the discoloring and sensitivity of two toes...one on each foot.
I saw the Podiatrist this am with very tender toes...
I'm shocked....Is this serious? and what should I do...? How did this happen? Does it mean I have some other underlying disease >
Thanks for listening...
Theresa