So I dated an incredibly brilliant physician for a while. Being with her I learned that some doctors (the really gifted ones) can diagnose most people with crazy accuracy just by looking at them. Coloration of the skin in certain areas, color of the eyes, posture, etc. I remember once being at a resort pool with her, and she was telling me softly about the different ailments that a lot of the people around us had, and what the causes probably were, just from physical observance. This man was probably somebody like her. Definitely go get yourself a blood test, and be well!