I don't know what 12.6 means but if it is you blood cell count in millions then it is extremely high...
found this on one of the medical sites)))
* Male: 4.7 to 6.1 million cells per microliter (cells/mcL)
* Female: 4.2 to 5.4 million cells/mcL
In cases of higher then normal RBC count it may mean the following:
* Congenital heart disease
* Cor pulmonale
* Dehydration (such as from severe diarrhea)
* Pulmonary fibrosis
* Polycythemia vera
Your doctor should tell you all the other information I think.