Helen,
Do you have the opportunity to speak with the doctor about the use of the term "history"? If the doctor documents hx of, but really means that the patient still has whatever the "hx of" may be, you should take the documentation back to the doctor and educate them on the use of the word history.
Under ICD-9 Guidelines, the term "history of" means that the patient no longer has the condition. Never use this term to describe a disease that the patient still has.
Now I understand that, since the patient is obviously still receiving medication for this condition, it is still a pertinent diagnosis. I'm unsure what kind of coding you do but, from my experience working in a physician office setting, I can tell you that we have had DXs that did not validate because of the use of the term "history" even though it was a chronic condition. Information in the subjective portion of the note clearly showed that the diagnosis was valid. However, in the Assessment portion, the diagnosis was written as "History of COPD" for example.