This study is a prospective, observational cohort study. The plan of this study is to consecutively enroll 2,000 primary headache patients who meet the inclusion criteria from the neurology outpatient department and inpatient department of Sun Yat-sen Memorial Hospital, Sun Yat-sen University. Basic clinical data registration, various scale evaluations, cranial imaging examinations, and collection of blood and fecal biological samples will be completed. During the 10-year follow-up plan, systematic clinical evaluations of the disease severity, diagnosis and treatment, living ability and health status of patients will be carried out regularly every 6 - 12 months. Imaging and other functional evaluations will be conducted when necessary. Data collection includes:

Demographic data (including age, gender, education, ethnicity, marital status, occupation, etc.); General clinical data (past medical history, medication history, personal history, menstrual and childbearing history, family history, etc.); Clinical data of primary headache: headache frequency, duration, severity (Numeric Rating Scale for pain, NRS), headache-related medication use, drug efficacy and side effects; Scale evaluations: MIDAS, HIT-6, BPI, MSQ, ADL, CDR, PGIC, CGIC, PHQ-4, mTOQ-4, ASC-12, MIBS-4, HARDSHIP, WHO-QOL BREF, HAMD, HAMA, TNQ; Records of neurological imaging examinations, blood sample and fecal sample collection.

Background Headache is one of the most common diseases in the nervous system. Approximately 52% of adults worldwide suffer from primary headache. The third edition of the International Classification of Headache Disorders in 2018 classified primary headache into migraine, tension-type headache, trigeminal autonomic cephalalgia, and other primary headaches. Although primary headache has no obvious organic lesions, it can lead to transient or permanent central nervous system dysfunction, affecting people's daily life and work, and imposing a huge economic burden on society. This study intends to establish a prospective cohort of patients with primary headache, observe the relevant risk factors, clinical treatment efficacy, and prognosis of patients with primary headache, and explore the relevant clinical factors and biomarkers for a favorable prognosis. During the 10-year follow-up plan, systematic clinical evaluations will be regularly carried out on the disease severity, diagnosis and treatment status, living ability, and health status of patients. When necessary, blood and fecal samples will be collected and imaging evaluations will be conducted to complete the construction of a clinical diagnosis and treatment information database for patients with primary headache, and analyze the clinical factors related to the prognosis.

Research Objectives To observe the risk factors, clinical characteristics, treatment regimens and their efficacy, and prognosis of patients with primary headache, and to explore the relevant clinical factors and biomarkers for a favorable prognosis.

Research Design This study adopts a single-center, prospective cohort design.

Baseline Assessment Demographic data (including: age, gender, education level, ethnicity, marital status, occupation, etc.); General clinical data (past medical history, medication history, personal history, menstrual, marital and childbearing history, and family history, etc.); Clinical data of primary headache: headache frequency, duration, severity (Numerical Rating Scale for Pain, NRS), past headache-related medication use, medication efficacy and side effects; Scale Evaluation: MIDAS, HIT-6, BPI, MSQ, ADL, CDR, PGIC, CGIC, PHQ-4, mTOQ-4, ASC-12, MIBS-4, HARDSHIP, WHO-QOL BREF, HAMD, HAMA, TNQ; Biochemical Indicators: White blood cell count and classification, inflammatory indicators in the blood; fecal bacteriological examination; Changes in Imaging Biomarkers: Changes in brain structure, brain function, and metabolism.

Follow-up Study

Within 6 months after enrollment, follow-up assessments will be conducted every 1-3 months; from half a year to 10 years after enrollment, follow-up assessments will be conducted every 6-12 months (the assessment methods include in-person interviews, telephone follow-ups, and online follow-ups). The following data will be collected:

Clinical data of primary headache: headache frequency, duration, severity (Numerical Rating Scale for Pain, NRS), the use of headache-related medications (types, dosages, efficacy, and side effects); Scale Evaluation: MIDAS, HIT-6, BPI, MSQ, ADL, CDR, PGIC, CGIC, PHQ-4, mTOQ-4, ASC-12, MIBS-4, HARDSHIP, WHO-QOL BREF, HAMD, HAMA, TNQ; Blood and fecal tests and cranial imaging examinations (when clinically necessary and with the patient's/family member's consent and cooperation).

Inclusion Criteria:

1. Age is less than 65 years old.
2. Meets the diagnostic criteria for relevant primary headaches (such as tension-type headache, migraine, cluster headache, trigeminal autonomic cephalalgia, etc.) in the third edition of the International Classification of Headache Disorders (ICHD - 3).
3. Is willing and able to participate throughout the entire study period and sign the informed consent form.
4. Has the ability to complete the "Headache Diary" independently or with the help of a guardian.

Exclusion Criteria:

1. Secondary headache
2. High - risk populations, such as those with severe heart disease, impaired liver and kidney function, malignant tumors, etc.
3. Patients with mental illness, cognitive impairment, or those who are unable to cooperate with the research requirements
4. History of intracranial lesions or other nervous system diseases (including stroke, epilepsy, etc.)

Primary headache is a common neurological disease worldwide, with a prevalence rate of approximately 10% - 20%. Its occurrence is not related to brain structural damage, infection, metabolic abnormalities, or other diseases, but is directly caused by the abnormal function of the central or peripheral nervous system. According to the ICHD-3, primary headache mainly includes migraine, tension - type headache, and cluster headache etc. The attack frequency, duration, and severity of primary headache show a high degree of heterogeneity. Primary headache is highly comorbid with anxiety, depression, and sleep disorders. The quality of life of patients with chronic primary headache significantly declines, and the work absenteeism rate and economic burden increase. Analgesic drugs are mainly used in the acute phase. Preventive treatment is applicable to patients with frequent or chronic attacks, and non-pharmacological interventions are also effective strategies.