Cluster HeadacheCluster headaches are headaches that typically occur at periodic intervals. Some of the most painful types of headaches, cluster headaches often come on without warning and cause severe pain with no apparent reason. Patients typically feel a headache on only one side of the head, which also affects the closest eye. Many describe the sensation as similar to having the eye pushed out of the socket.

Since cluster headaches occur for no apparent reason, they can be difficult to treat. However, some patients respond favorably to medical marijuana use, which may reduce the severity and frequency of the attack.