Cluster Headaches/Migraines is what my Doc tells me. Lucky for me I have had Migraines in the past due to types of lighting. So have kept Excedrin Migraine meds in all vehicles I drive plus around the house but the pills have been pulled off the market and I'm almost out. Cluster Headaches for me feel like a Migraine coming on and last 3-4 days even with meds. the Migraines I gotta take meds cover my head to block out sound and light and hope I can sleep for a few hours till it's gone.