Which type of headache typically has an episodic pattern and can be very severe?

Cluster headaches are characterized by their episodic nature, occurring in cyclical patterns or clusters. These headaches often involve excruciating pain, typically located around one eye or one side of the head. The intensity of the pain is a hallmark of cluster headaches, leading sufferers to describe them as one of the most severe types of headaches. During a cluster period, individuals may experience multiple headaches in a day, often at the same time each day.

In contrast, tension headaches are usually milder and tend to be more chronic rather than episodic in nature. Migraines, while also episodic and capable of being very severe, often come with associated symptoms such as light sensitivity, nausea, and aura. Chronic daily headaches, on the other hand, refer to headaches occurring 15 days or more per month but lack the severe characteristics and episodic nature seen in cluster headaches. Thus, the defining features of cluster headaches make them the correct answer to the question regarding the type of headache that is episodic and particularly severe.