How many diagnostic codes are there? how many that have to with heart, stroke, diabetes, end stage renal, and organ transplants and cancer.

Depends on database: The most commonly used disease diagnosis database in the us is the icd-9 code book. See http://en.Wikipedia.Org/wiki/list_of_icd-9_codes for details. However billing systems are slowly switching over to a newer database called icd-10 which has about 10 times more codes. There are also umls and snomed-ct diagnosis, symptoms and sign codes.