What is the common feature of all classic migraines?

The defining characteristic of classic migraines is indeed the presence of an aura. An aura consists of visual disturbances, sensory changes, or motor symptoms that typically precede or accompany the headache phase. This feature is significant in distinguishing classic migraines from other types, such as common migraines, which do not involve an aura. It's important to recognize this aspect because the presence of an aura can provide valuable insight into the severity and nature of the migraine, and it's often associated with more intense headaches.

While migraines can affect both genders, they are not exclusively found in women, and their occurrence is not limited by gender. Frequent vomiting can occur with some migraines but is not a universal feature of all classic migraines; it varies from person to person. Additionally, the duration of migraine attacks can be quite variable, often lasting for several hours to days, making the notion of a duration of less than 2 hours not applicable to all classic migraines. Thus, the presence of aura stands out as the unifying characteristic across all classic migraine cases.