Risk Factors & Causes for Migraine

Many people think of migraine as a severe headache, but a migraine is actually a common neurological disorder. Neurological means a condition that involves the nerves or nervous system.

Doctors do not know exactly what causes migraine. Research points to several different potential causes. There are also several risk factors that increase the chances of developing migraine or occasional migraine turning into chronic migraine.

For example, migraine often runs in families. This means that certain genetic changes seem to increase the chances of developing migraines. These genes may make the person’s brain more likely to react to things in their life that trigger an attack.1

Risk factors for migraine

In addition to a family history of migraine, there are several other things that increase your chances of developing chronic migraine. These risk factors include:2

  • Being female
  • Snoring
  • Lower education level
  • Head injury
  • Using too many pain relievers
  • Drinking caffeine
  • Life stresses
  • Being unemployed

Having depression, anxiety, or a body mass index (BMI) of 30 or more greatly increases the chances of developing a daily headache.2

Causes of migraine

But when an attack happens, what changes happen in the body to cause migraine? The most common ideas for what causes migraine are:3

  • Cortical spreading depression
  • Triggers to the trigeminovascular system
  • Nerve cell sensitization
  • How the body processes the CGRP brain chemical
  • How the body processes the brain chemical serotonin
  • Changes to the heart muscle

Cortical spreading depression

Cortical spreading depression is the medical term for a slow wave of electrical activity in the neurons of the brain. Neurons are specialized brain cells that send signals to other types of cells.3,4

Cortical spreading depression may be the cause of migraine auras. In addition, these slow electrical waves can activate the nerves responsible for sensing pain in the covering surrounding the brain (called the “meninges”) and also change the function of blood vessels, both of which can lead to migraine pain.3,4

Trigeminovascular system

The trigeminovascular system is a group of nerves that sense pain in the face and covering of the brain. These nerves send signals to blood vessels in the brain and spinal cord. In people who have migraine, this system releases brain chemicals that cause inflammation and changes to blood vessels. The trigeminovascular system is thought to play a role in how long and how intense a migraine is. The inflammation may lead to a condition called sensitization.3

Sensitization

Sensitization happens when neurons in the brain become more and more sensitive to stimulation. Neurons are specialized brain cells that send signals to other types of cells. This sensitivity leads to a person being more easily triggered, having a stronger response to known triggers, and reacting to new and different migraine triggers.

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Sensitization is thought to be one of the reasons behind occasional migraine turning into chronic migraine. It may be responsible for many of the symptoms of migraine, such as throbbing pain, pain that gets worse with a cough or movement, and sensitivity to light or sound.3

Calcitonin gene-related peptide (CGRP)

CGRP is a brain chemical found in nerve cells. CGRP seems to control how the trigeminovascular system sends pain signals. If the brain of a person with migraine releases too much CGRP, it can trigger a migraine attack. CGRP levels also play a role in the severity of a migraine.3

Serotonin

Serotonin is a chemical the body produces naturally. It sends signals between nerve cells and helps the body control how the blood vessels contract. It plays a role in controlling moods, sleeping, eating, and digestion. Too much serotonin may play a role in migraine by causing too much activity in the brain’s neurons and triggering cortical spreading depression.3,5

Changes in the heart muscle

Studies have found that certain changes to the heart muscle may trigger migraine with aura. This includes some people who have heart surgery and those living with certain heart conditions.

Migraine triggers

Many people with migraine learn that certain behaviors or foods trigger their attacks. Some common triggers include:1,3

  • Bright light or glare
  • Weather changes
  • Changes in routine
  • Skipping meals
  • Lack of sleep
  • Dehydration
  • Loud sounds
  • Strong smells

Doctors do not fully understand why these triggers lead to cortical spreading depression or other reasons for migraine.

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Written by: Jessica Johns Pool | Last reviewed: October 2020