Cluster headaches affect one side of the head (unilateral) and may involve tearing of the eyes and a stuffy nose. The headaches occur repeatedly every day at the same time for several weeks and then go away. Some of the causes of cluster headaches may include: Some medications (such as nitroglycerin) heavy smoking, an interruption in your normal sleep pattern Problems with the hypothalamus, which controls your body's "biological clock" The first attack most frequently arises during adolescence or the early 20s. Many patients report that alcohol triggers an attack. Others report that stress, glare, or ingestion of specific foods may trigger an attack. There is usually no family history of similar headaches. A typical cluster headache starts suddenly and without warning