What Is Happening in the Brain During a Migraine?

Medically Reviewed on 5/18/2022
what causes migraine
During a migraine, some chemicals in the brain become more active, which send out confusing signals that result in headaches.

Some chemicals in the brain become more active, causing parts of the brain to send out confusing signals that cause migraine symptoms.

The precise chemical changes in the brain are unknown; however, something may cause a change in the activity of some brain chemicals, resulting in a migraine attack.

  • Glutamate:
    • Massive quantities of glutamate, a critical neurotransmitter in the brain, could help explain migraine onset.
    • An aberrant release of glutamate into the extracellular space (the space between brain cells) can cause spreading depolarizations or tsunami-like waves of activity that spread across the brain, resulting in a migraine. Glutamate is a neurotransmitter that acts as a signal between nerve cells.
    • However, too much glutamate can excite cells and destroy them.
  • Dopamine:
    • Although the exact cause of migraines is unknown, an imbalance in a brain neurotransmitter is thought to play a role.
    • Dopamine is a neurotransmitter that affects movement, emotions, motives, and sensory perceptions, as well as the ability to moderate pain.
    • Researchers at the University of Michigan have discovered that dopamine levels in the brain decrease during a migraine attack compared with their baseline level between attacks.
    • Additional research is needed to confirm the findings and determine how they may be used to build more effective migraine treatments, according to the researchers.
  • Serotonin:
    • In people with migraine, serotonin (another neurotransmitter) is low between attacks and spikes during the attack.

Migraine is now classified as a neurological disorder and the sixth most disabling disease in the world, according to the Migraine Research Foundation.

What causes migraines?

Although studies have reported that a migraine is a biological disorder of the brain that causes recurring moderate to severe headaches, the exact cause of it remains unknown.

There are, however, few studies and theories regarding the various causes of migraine caused by malfunctions in brain functions:

  • Constriction of the blood vessels:
    • When blood vessels in the brain constrict, they can cause pain by direct irritation of the nerve endings or by reducing oxygen supply to nearby tissue leading to a migraine.
    • Although some migraines appear to be genetically linked, the underlying cause of migraines remains a mystery.
    • According to current research, people with migraine have a more sensitive nervous system than the general population.
  • Role of the trigeminal nerve:
    • Excitation of a nerve responsible for sensation in the face could be one of the causes. The trigeminal nerve is stimulated by various neurotransmitters.
    • As a result, the blood vessels that surround the brain expand and inflame.
    • These blood vessels are connected to nerve fibers that send pulsations from the blood vessels back into the brain, where you perceive it as pain.
    • This system is vulnerable to being activated repeatedly when there is no good reason in people with a migraine.
    • Instead of serving as a protective mechanism, it has evolved into a system that interferes with your ability to function normally in your life.
  • Cortical spreading depression:
    • According to one widely accepted theory, migraines are caused by rapid waves of brain cell activity crossing the cortex (the thin outer layer of brain tissue), followed by periods of no activity. This phenomenon is known as cortical spreading depression.
    • According to evidence, it causes inflammatory and other processes that stimulate pain receptors on the trigeminal nerves.
    • This “neurogenic” inflammation and the release of other factors make the receptors and parts of the brain that receive their signals more sensitive, increasing the likelihood of a migraine.
    • According to some researchers, migraines begin lower in the brain, in the brainstem, which controls basic functions such as respiration and pain responses, as well as modulates many others, including incoming sensory information.
    • According to the theory, if certain areas of the brainstem aren't working properly or are easily excited, they're capable of triggering cascades of neurological events, such as cortical spreading depression, which account for migraine's various symptoms.
  • Gray matter (GM) changes:
    • Functional imaging studies on people with migraine have revealed changes in several brain GM regions.
    • Such GM changes include areas of decreased and increased density, and they are most likely related to pathological substrates associated with this disease.
  • Brain lesions:
    • According to an American Medical Association study, frequent migraines are associated with an increased risk of brain lesions.
    • However, more research is needed to determine whether lesions hurt the health and whether they are caused by migraine attacks.
  • Traumatic brain injury:
    • It is estimated that between 30 and 90 percent of traumatic brain injuries, such as those sustained in sports, military service, vehicle accidents, falls and domestic abuse, resulting in a post-traumatic headache.
    • More than half of people with mild to moderate brain injuries fit the migraine criteria.
    • Migraine can impair cognitive function, emotional stability, and social connections.
    • Migraine-like symptoms are typical in post-traumatic headaches that do not resolve quickly.
    • They are usually more severe and resistant to treatment. Migraine is now one of the top 10 causes of military disability.
  • The migraine brain does not get used to repeated stimulations:
    • If you flash a light in the eyes of someone who does not have a migraine regularly, their brain will ultimately reduce its response.
    • For people with migraine, the brain keeps reacting over and over. This lack of adaptability has been observed with light and sound.
    • This may cause people with migraine to use more energy being aware of their surroundings. In principle, an overabundance of a stimulus could result in an attack.


Who suffers more frequently from migraine headaches? See Answer

8 types of migraines

Experts classify migraines into different types, which might help plan a specific treatment.

The eight types of migraine include:

  1. Migraine without aura:
    • Symptoms include:
      • Throbbing pain that begins on one side of your head (for many people, it begins behind the left eye)
      • Moving around makes the pain worse
      • Nausea
      • Dizziness
      • Sensitive to light but not sound
      • The duration can range from 4 to 72 hours
  2. Migraine with aura:
    • Before an attack begins, visual disturbances occur, followed by common migraine symptoms.
      • The duration can range from a few minutes to an hour, and it usually occurs before the migraine attack begins.
      • The attack itself can last anywhere between 4 and 72 hours.
    • The International Classification of Headache Disorders (ICHD-3) breaks migraine with aura even further into four types:
      • Typical aura: Can bring on visual symptoms such as
        • Temporary blind spots
        • Geometric patterns
        • Zigzag lines
        • Stars or shimmering spots
        • Flashes of light
      • Brainstem aura: Involves symptoms that seem to originate in the brainstem such as
      • Hemiplegic migraine: Involves symptoms such as
        • Motor weakness or loss of muscle strength, usually on one side of your body
        • Struggle with language
        • Feel confused or tired
      • Retinal or ocular migraine or optical migraine:
        • In contrast to a typical migraine with aura, you only have visual disturbances in one eye.
        • Because it causes visual problems, it is also known as ocular migraine or optical migraine.
  3. Menstrual migraine or hormonal migraine:
    • Symptoms occur at the same time as your period.
    • The duration can range from 4 to 72 hours.
    • Migraine attacks in women are caused by hormonal fluctuations.
    • ICHD-3 states that menstrual migraine can occur with or without aura and usually occurs just before or at the start of your period.
    • Menstrual migraine attacks, which affect 7 to 19 percent of women, may be triggered by a rapid drop in estrogen and progesterone that occurs before your period begins.
    • However, most women who have menstrual migraine also have headaches at other times of the month.
    • Menstrual migraine attacks are more painful and last longer than nonmenstrual migraine attacks.
  4. Vestibular migraine:
    • Symptoms may include:
      • Vertigo
      • Dizziness
      • Duration can range from a few seconds to several days
      • Surprisingly common and affects 30 to 50 percent of people with migraine
      • Can occur when you move your head or see something particularly stimulating
  5. Migraine without headache or silent migraine or painless migraine or acephalgic migraine:
    • Symptoms can last for an hour or less.
    • Migraine without pain can have all the same symptoms as migraine with aura, with the exception that the headache never appears.
    • According to the American Migraine Foundation, migraine attacks without headaches become more common as you get older.
  6. Abdominal migraine:
    • Instead of a headache, the main symptom is stomach pain.
    • The duration can range from 1 to 72 hours.
    • Abdominal migraine is more common in children than in adults, despite two-thirds of them developing migraine headaches as adolescents.
    • According to the American Migraine Foundation, abdominal migraine causes pain near the navel, as well as nausea, loss of appetite, vomiting, and a pale appearance.
    • Abdominal migraine, like common migraine, can be triggered by stress, bright lights, and food additives such as monosodium glutamate.
    • It is typically treated with the same medications that are used to treat standard migraine attacks with headaches.
  7. Status migrainosus:
    • It is a migraine attack that lasts more than 72 hours and may or may not is accompanied by an aura.
    • According to ICHD-3, overuse of migraine medications is a possible cause. Other triggers, however, can cause them.
  8. Sinus migraine:
    • According to one study, more than 80 percent of people with sinusitis meet the criteria for migraine disease.
    • The activation of the trigeminal–autonomic reflex is thought to cause sinus-like symptoms such as mid-facial pain, stuffy nose, nasal drainage, and loss of smell.
    • The presence of sinus-like symptoms in conjunction with ICHD-3 migraine diagnostic criteria suggests that sinus migraine is the most likely diagnosis.

2 stages of migraines

A typical migraine is divided into two stages:

  1. The trigeminal nerve is activated:
    • When the trigeminal nerve becomes stimulated, the most common initial symptom is pain around the eye and temple.
    • If the pain is treated quickly with migraine medications such as triptans, inflammation can be reduced, and the migraine can be terminated relatively quickly.
  2. The central nervous system is triggered:
    • If left untreated, another pain mechanism in the central nervous system will be activated.
    • At this point, turning off the pain mechanism becomes extremely difficult.
    • Medications are less likely to work at this point.

4 phases of migraines

Migraines are unique in that they have distinct phases; however, not all people have each phase.

Phases of a migraine headache may include:

  1. Premonition phase:
    • A shift in mood or behavior could occur hours or days before the headache.
  2. Aura phase:
    • One-third of people who have migraine headaches report an unusual “feeling” or aura before the headache.
    • The aura phase is characterized by visual, sensory, or motor symptoms that appear just before the headache.
    • Hallucinations, numbness, changes in speech, visual changes, and muscle weakness are some symptoms.
  3. Headache phase:
    • The pain is throbbing on one or both sides of the head. It is common to be sensitive to light and motion.
    • Depression, fatigue, and anxiety are also symptoms.
  4. Headache resolution phase:
    • During this stage, the pain subsides.
    • However, it may be replaced by fatigue, irritability, and difficulty concentrating.
    • Some people feel revitalized following an attack, whereas others do not.

The exact cause of a migraine headache is unknown. Many experts believe that an imbalance in brain chemicals such as serotonin, as well as changes in nerve pathways, is to blame. Migraines may run in families, implying a genetic connection.

Should I go to the ER for a migraine?

The pain threshold varies from person to person, but if a person has a severe headache with or without nausea and vomiting and experiences loss of vision or weakness inside the body, they should go to the emergency room.

  • Individuals typically describe the pain on one side of the head as severe throbbing and pulsating (pain in a series of regular beats or rhythm).
  • Migraine symptoms vary from person to person; generally, migraine headaches last about four hours, but if severe, they can last for more than three days, during which time a person should see a doctor regardless of the intensity of the pain.
  • Some people experience migraine headaches every few days, whereas others only experience them one or two times a year.

5 treatment options for migraines

People with migraine can use a triptan drug to stop an attack. Triptans appear to work by inhibiting pain signaling in the brainstem. They should only be taken after consulting a physician.

Here are five other treatment options for migraines:

  1. Medication for pain and nausea:
  2. Preventive medications:
  3. Biofeedback:
    • This technique assists you in recognizing stressful situations and can help you stop a migraine attack.
  4. Transcranial magnetic stimulation:
    • When placed on the back of your head, this device reduces or eliminates pain.
  5. Lifestyle modifications:
    • Doctors usually recommend lifestyle changes and hormonal therapy to reduce the frequency and intensity of migraines.
    • Resting in a dimly lit room during migraine symptoms may help.
    • Stress management and reduced exposure to bright lights may help some individuals.

Consider what might have triggered the attack and avoid that trigger. Inquire with your doctor about treatment options for preventing or reducing attacks.

Although research is limited, complementary treatments may be beneficial for some. Acupuncture and aromatherapy are two examples of relaxation techniques (yoga and meditation).

Subscribe to MedicineNet's General Health Newsletter

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

Health Solutions From Our Sponsors

Medically Reviewed on 5/18/2022
Image Source: iStock Images

How a Migraine Happens: https://www.hopkinsmedicine.org/health/conditions-and-diseases/headache/how-a-migraine-happens#:

The neurobiology of migraine: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5494713/

Brain scans show dopamine levels fall during migraine attacks: https://news.umich.edu/brain-scans-show-dopamine-levels-fall-during-migraine-attacks/

The Chronic Migraine Brain: What Have We Learned From Neuroimaging? https://www.frontiersin.org/articles/10.3389/fneur.2019.01356/full

Migraine Brain: https://www.brainfacts.org/thinking-sensing-and-behaving/pain/2014/migraine-brain

The science of migraines: https://www.science.org/content/article/science-migraines