Migraine Frequency: Episodic vs Chronic Migraine
Reviewed by: HU Medical Review Board | Last reviewed: July 2022 | Last updated: May 2023
Migraine is a relatively common but disabling headache disorder. Women are 2 to 3 times more likely to be living with migraine than men. One study found that migraine is one of the most common causes of disability worldwide.1
Everyone experiences migraines slightly differently. And one person may even experience multiple kinds of migraine throughout their life. Migraines can be categorized by:2
- Their frequency
- The presence or absence of an aura
- Where on your head you experience the pain
In this article, we will discuss the frequency of migraines.
What is episodic migraine?
Episodic migraine is traditionally defined as less than 15 headache days per month. This definition was originally created so that migraines could be more easily compared with tension headaches. However, a 2021 study looked at migraine frequency and its connection to quality of life. In this study, the researchers divided participants into 4 groups by how many headache days they had per month:3
- 0 to 7 days
- 8 to 14 days
- 15 to 23 days
- 24 or more days
Less than 8 headache days per month was shown to have a significantly smaller effect on quality of life. Though their research is early, the researchers feel that the difference between episodic and chronic migraine should be defined at 8 headache days a month instead of 15.3
What is chronic migraine?
Chronic migraine is defined as having more than 15 headache days per month for at least 3 months.3
These migraine categories exist so that doctors can better understand and treat the headache symptoms that people experience. But the researchers who conducted the 2021 study thought that the current migraine categories might not be accurate. They found that people who had 8 to 14 headache days per month and those who had 15 to 23 headache days per month had similar effects on their quality of life. In the current system, these individuals would be split between the episodic and chronic migraine categories. The researchers hope to complete more research to understand if these categories need to change.3
They also found that those who lived with headaches for more than 24 days per month were severely affected by those headaches. They affected quality of life and their ability to hold down a job. The study concluded that more research was necessary to find more effective treatments for this group.3
What is chronification or transformation?
If you are living with migraine, you may find that your migraines may always be very similar, or they may feel a bit different every time. You may also find that the frequency of your migraines changes. Some people may transition from having episodic to chronic migraines. This process is called “chronification” or “transformation.”2
You may be more likely to experience chronification if you:2
- Have other pain disorders
- Are female
- Have a history of head or neck injury
- Are experiencing stressful life events
- Frequently use medicine to stop your migraines
- Have other disorders such as: Depression, snoring, sleep issues, asthma
The good news is that those living with chronic migraine may also transition back to having episodic migraine. This can happen in anywhere from 26 to 70 percent of people living with migraine.2
What does this mean?
Unfortunately, patients living with chronic migraine are more likely to experience anxiety and depression. They also are more likely to experience a lower quality of life than people living with episodic migraine. If you are having problems with your mood or mental health – regardless of how frequent your migraines are – reach out for help. You are not alone and there are resources to help you.3
Your doctor may ask you to keep a migraine journal where you record your symptoms daily for a month or more. This can help your doctor understand what migraines are like for you.4
If you have any questions about your experience living with migraines, speak to your doctor.