What does a line down the center of your tongue mean?

Your tongue can actually tell a lot about your health, search tongue diagnosis TCM

Traditional Chinese Medicine,

I suggest you visit a Chinese acupuncturist, and have them look at it, they can tell you the exact cause, and what its indicating.

Check this link below for more information.

http://www.sacredlotus.com/diagnosis/tongue/index.cfm

Look on another website