Medical Jargon – Meant To Be Mysterious?

I grew up hearing jokes about doctors’ handwriting.  I tried to read their scripts–simply described as unintelligible.  Only years later would I learn that their I’s, V’s, and X’s were Roman numerals.  Furthermore, their ibids and et ceteras were Latin.  Silly me didn’t realize they were using a dead language not spoken anywhere for centuries except at mass.  Well, the people in billing solved the handwriting problem with codes–alphabetic and numerical.  The only problem is that there is no explanation for what those abc’s and 1-2-3′s mean.  Do I have to enroll in one of those medical coding training courses to find out my diagnosis before I send it on to my insurance company?