What characterizes a classic migraine headache compared to a common migraine?

A classic migraine headache is characterized by the presence of visual auras, which are sensory disturbances that can precede the headache. These auras may manifest as visual changes such as flashing lights, zigzag patterns, or temporary loss of vision, and typically occur within 30 minutes to an hour before the headache starts. This is a key distinguishing feature from common migraines, which do not involve auras.

While nausea and vomiting, unilateral pain, and the potential for headache onset during physical activity are symptoms that can occur with both classic and common migraines, they are not exclusive characteristics that differentiate the two types. Thus, the association with visual auras is the defining feature that differentiates a classic migraine from a common migraine.