Final answer:
The patient's history of hypertension and diabetes should be recorded in the Past Medical History section of the EMR, which is used to document a patient's chronic conditions and previous medical issues.
Step-by-step explanation:
A patient with a headache who has a history of hypertension and diabetes would have this information recorded in the Past Medical History section of their Electronic Medical Record (EMR). The Past Medical History section is dedicated to recording the patient's personal medical history, including chronic conditions, previous medical diagnoses, surgeries, and significant past illnesses. This information is crucial for healthcare providers to develop an understanding of the patient's overall health status and to deliver appropriate care.