Bouts of frequent attacks, known as cluster periods, may last from weeks to months, usually followed by long periods of relief (remission). During remission, attacks may stop for months or years.
Pain is severe on one side of the head, accompanied by symptoms such as nasal discharge, or red or tearing eyes.
Injected medications, inhaled oxygen, steroids, and preventive medications can help.
Consult a doctor for medical advice
Sources: Mayo Clinic and others.
More than 200,000 US cases per year
Treatable by a medical professional
Requires a medical diagnosis
Lab tests or imaging not required
Chronic: can last for years or be lifelong