Episodic Migraine Definition Jun 2026
According to the published by the International Headache Society (IHS), Episodic Migraine is defined by the frequency of attacks and the presence of specific symptom criteria.
15 or more headache days per month for at least three months, where at least 8 of those days meet full migraine criteria. Episodic Migraine Chronic Migraine Frequency < 15 days per month 15+ days per month Persistence Intermittent attacks with clear breaks More persistent and often more intense Prevalence More common form of migraine Affects a smaller percentage of migraineurs Progression Can progress to chronic (approx. 3% annually) Can revert to episodic with treatment Source: Healthline , American Migraine Foundation Phases of an Episodic Migraine Attack
fewer than 15 headache days per month . Unlike chronic migraine , which involves 15 or more days of headache per month, episodic migraine is characterized by distinct attacks with symptom-free intervals in between. Miles For Migraine +3 Review of Episodic Migraine 1. Classification and Frequency Medical professionals further categorize episodic migraine based on the monthly frequency of attacks to determine the best management strategy : Low-Frequency Episodic Migraine (LFEM): Fewer than 10 migraine days per month. High-Frequency Episodic Migraine (HFEM): 10 to 14 migraine days per month. This group often experiences a disability level similar to chronic migraine . 2. Clinical Features and Phases An episodic migraine attack is a complex sensory process typically consisting of four overlapping phases: 10 sites Comprehensive Guide to Managing Episodic Migraine Mar 27, 2024 — episodic migraine definition
At least one of the following: nausea and/or vomiting, sensitivity to light (photophobia), or sensitivity to sound (phonophobia). Episodic vs. Chronic Migraine: The 15-Day Threshold
The 15-day threshold is not arbitrary—it has clinical, prognostic, and therapeutic implications. According to the published by the International Headache
| Feature | Episodic Migraine | Chronic Migraine | | :--- | :--- | :--- | | | < 15 days | ≥ 15 days (for >3 months) | | Prevalence | ~90-95% of people with migraine | ~5-10% of people with migraine | | Disability | Lower (typically interictal normal function) | Higher (often daily impairment) | | Treatment approach | Acute (abortive) + prevention if needed | Preventive treatment essential; limit acute meds | | Risk of progression | Lower (but modifiable risk factors exist) | Higher (can reverse to EM with treatment) |
An attack often involves more than just the headache phase. Many individuals experience four distinct stages: Unlike chronic migraine , which involves 15 or
Note on "Transformation": Approximately 2.5% of patients with Episodic Migraine progress to Chronic Migraine each year. Risk factors include overuse of acute medication (medication-overuse headache), obesity, depression, and high baseline headache frequency.