<unk>  <unk>  is a primary<unk>  syndrome which can mimic chronic migraine and chronic tension-type<unk> . The<unk>  is<unk>  and unremitting from very soon after onset (within 3 days at most), usually in a person who does not have a history of a primary<unk>  disorder. The pain can be intermittent, but lasts more than 3 months.<unk>  onset is abrupt and people often remember the date, circumstance and, occasionally, the time of<unk>  onset. One retrospective study stated that over 80% of patients could state the exact date their<unk>  began. The cause of<unk>  is unknown, and it may have more than one etiology.<unk>  onset is commonly associated with an infection or flu-like illness, stressful life event, minor head trauma, and extra cranial surgery. Infection or flu-like illness and stressful life event are most often cited. The pathophysiology of<unk>  is poorly understood. The syndrome is difficult to treat and may persist for years. The age of onset ranges from 6 to greater than 70 years old, with a mean of 35 years. It is found to be more common in females in both the adult and pediatric populations.<unk>  is rare. The Akershus study of chronic<unk> , a population based cross sectional study of 30,000 persons aged 30–44 years in Norway, found a one-year prevalence of 0.03 percent in the population. In 1986, Vanast was the first author to describe the<unk>  <unk>  as a benign form of chronic<unk><unk>  (CDH). The criteria for the diagnosis of<unk>  were proposed in 1994 (the Silberstein–Lipton criteria) but not included in the International Classification of<unk>  Disorders (ICHD) until 2004.
New daily persistent headache
Chronic subjective dizziness
symptoms of Migraine
symptom of Migraine
Long-term depression
Headache attributed to a substance or its withdrawal
Acute visual loss
symptom of Cluster headache