Personal history of DVT vs active DVT
You are correct, active conditions should not be reported with a history code, but a code for the current condition. If the condition is still present, do not report a history code.
ICD-10-CM Official Guidelines for Coding and Reporting 2017, page 27:
"There are two types of history Z codes, personal and family. Personal history codes explain a patient’s past medical condition that no longer exists and is not receiving any treatment, but that has the potential for recurrence, and therefore may require continued monitoring."