Migraine
- Reviewed by Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing
What is it?
Migraine is a very common, but very particular, type of headache. Most people who have migraine experience repeated attacks of headaches that occur over many years. The typical migraine headache is throbbing or pulsating, and often is associated with nausea and changes in vision. While many migraine headaches are severe, not all severe headaches are migraines, and some episodes can be quite mild.
Up to 20% of people in the United States will experience migraine headaches at some point in life. In about half of those, migraine headaches first appear during childhood or adolescence. Two-thirds of people who get migraines are women, probably because of the influence of hormones. Migraines also tend to run in families.
The pain of migraines is associated with swelling in blood vessels and irritation of nerves that surround the brain, but these features do not explain what causes migraine. Instead, many experts now believe that cortical spreading depression is the likely inciting phenomenon. Altered electrical waves start to spread slowly across the brain, triggering a complex reaction involving the trigeminal nerve and its surrounding tissues.
Scientists have discovered an array of chemicals released during a migraine attack. Some of these substances have provided potential targets for new therapies.
The brain chemical serotonin may play a role in this process as it does in other conditions, including depression and eating disorders.
Symptoms
A migraine usually is a throbbing headache that occurs on one or both sides of the head. The headache typically is accompanied by nausea, vomiting, or loss of appetite. Activity, bright light, or loud noises can make the headache worse, so someone having a migraine often seeks out a cool, dark, quiet place. Most migraines last from four to 12 hours, although they can be shorter or much longer. One unique feature of migraines is an unusual sensation that a migraine is about to occur. This sensation is called a prodrome. Prodrome symptoms can include fatigue, hunger, and nervousness. Migraines also have typical aftereffects, such as a feeling of exhaustion that lasts a day or two after a severe migraine headache has faded. Not all people who get migraines have prodromes or aftereffects.
Another unique feature of migraines is an aura. In a typical aura, a person suddenly will develop blurry or distorted vision or will see pulsating lights. These changes in vision will come and go over 15 to 30 minutes and alert someone that a headache is about to begin. Sometimes, auras affect the sense of hearing, smell, or taste. Only some people who get migraines have auras, and they don't accompany every headache. An aura also can occur without being followed by a headache. Rarely, migraines can cause unusual neurological symptoms such as dizziness, loss of vision, passing out, numbness, weakness, or tingling.
Migraines can be triggered by certain activities, foods, smells, or emotions. Some people are more likely to experience migraines when they are under stress, while others develop migraines when stress is relieved (for example, the day after exams or an important meeting). Women who have migraines often find that their headaches occur or worsen around the time of their menstrual periods.
Diagnosis
A doctor usually will diagnose migraine based on your history and symptoms. In most cases, a physical and neurological examination will be entirely normal.
There are no special tests to diagnose migraines. For example, a computed tomography (CT) or magnetic resonance imaging (MRI) scan of the brain usually will be normal. However, your doctor may recommend additional testing if your headaches have features that are not typical for migraines, or if you develop other worrisome symptoms. If there is any doubt about your diagnosis, your doctor also may recommend a consultation with a neurologist, a doctor specializing in illnesses of the nerves and brain.
Expected duration
Migraine headaches can last from a few hours to a few days. A typical migraine sufferer will have several headaches each month. However, some people have only one attack in a lifetime, while others have more than three attacks per week.
Prevention
Not all migraine headaches can be prevented. However, identifying your headache triggers can help to reduce the frequency and severity of migraine attacks. Common migraine triggers include
- caffeine (either using too much or cutting back on regular use)
- certain foods and beverages, including those that contain tyramine (aged cheeses and meats, fermented beverages); sulfites (preserved foods, wines); and monosodium glutamate (MSG), a common flavor enhancer
- stress, or relief from stress
- hormone levels (menstrual cycles, hormone-containing medication such as birth control pills or estrogen)
- lack of sleep or disrupted sleep patterns
- travel or changes in weather or altitude
- overuse of pain-relieving medications.
Even if you avoid all possible triggers, you are still likely to experience a migraine occasionally. And many people who get migraines have frequent and severe headaches no matter how well they avoid triggers.
Other methods some people have used to decrease their migraine attacks include biofeedback, yoga, acupuncture, massage, and regular exercise.
Treatment
How your migraines are treated will depend on the frequency and severity of attacks. People who have a headache several times per year often respond well to nonprescription pain relievers. However, other therapies should be considered when headaches are disabling enough to interfere with usual activities and pain relievers don't work well.
There are two types of medications to treat migraines — drugs that are taken when a headache starts (called abortive medications) and drugs that are taken every day to prevent migraines (called preventive medications). The decision of whether to take a daily preventive medication or abortive medications is a personal choice. In the past, daily preventive medication was prescribed when a person had an average of two or more migraines per month. Today, reasons for prescribing preventive medication include
- infrequent attacks that don't respond well to abortive medications
- attacks that occur too often
- overuse of abortive medications or common pain relievers
- adverse reactions to abortive medications
- cost, including costs related to missing work
- migraines associated with unusual neurological symptoms (complicated migraines).
Abortive medications
When possible, an abortive medication should be taken immediately after an aura or migraine headache starts. This can be a challenge for people with frequent auras or headaches because overusing abortive medications can lead to chronic daily headache, a headache disorder that describes headaches that occur day after day without a specific cause or diagnosis.
Several nonprescription drugs and some relatively inexpensive prescription drugs are available. Aspirin, ibuprofen (Advil, Motrin, and other brand names), or naproxen (Aleve) taken at the earliest warning may be enough to stop a full-blown headache. Drug combinations often work better than drugs with a single active ingredient. One popular remedy for migraines is the combination of aspirin, acetaminophen, and caffeine (Excedrin) taken once or twice per month when symptoms occur.
Other medications require a prescription. Examples include isometheptene (Midrin and other brand names); medications called triptans, such as sumatriptan (Imitrex), naratriptan (Amerge), zolmitriptan (Zomig), and rizatriptan (Maxalt); and medications called ergotamines, such as sublingual ergotamine (Ergomar) and dihydroergotamine (Migranal). In addition, people who experience nausea with or without vomiting also can take an anti-nausea pill or suppository.
A newer class of drugs for migraine called CGRP antagonists (inhibitors), also known as gepants, work by blocking specific CGRP pain receptors in the nervous system. Ubrogepant (Ubrelvy) and rimegepant (Nurtec) are oral medications that can be taken for acute migraine treatment. The nasal spray Zavzpret containing the gepant called zavegepant is also available for pain relief.
If the headache becomes more intense and does not respond to one or two doses of an abortive medication, other pain relievers can be used to lessen the discomfort. The type and amount of pain reliever you should take varies depending on how you responded to the medication previously and how much other medication you took when the headache started.
Preventive medications
Many drugs are listed as potentially useful to prevent recurrent migraine attacks. The following are prescribed most frequently:
- Beta blockers — Propranolol (Inderal) and nadolol (Corgard) have a good track record of being safe and effective. Metoprolol (Lopressor) and atenolol (Tenormin) are reasonable alternatives.
- Calcium-channel blockers — Verapamil (Calan, Isoptin) is a popular choice. However, the medical evidence supporting its effectiveness is not as strong compared to other drugs.
- Anticonvulsants — Of the drugs in this class, topiramate (Topamax) is often the initial choice.
- Antidepressants — Two that are commonly used are venlafaxine (Effexor) and the tricyclic antidepressant amitriptyline (Elavil). Tricyclic antidepressants can be very effective, but often have troublesome side effects such as sedation, blurred vision, dry mouth, and constipation.
Some people with migraine have very frequent headaches, sometimes every day. This form of migraine, called chronic migraine, is difficult to treat. Your doctor may recommend a trial of Botox (onabotulinumtoxinA). The doctor gives multiple injections around the head and neck once every 12 weeks. It is approved for people that experience migraine headaches more than 14 days per month.
Your doctor may discuss the newer preventive therapies for people with very frequent attacks or chronic migraine. They are known as CGRP antagonists, such as galcanezumab (Emgality), erenumab (Aimovig), and fremanuzumab (Ajovy). You inject one of these medicines, usually monthly, under your skin.
Preventive medications (except for Botox injections) need to be taken every day to be effective. In choosing which medication to try first, you and your doctor will evaluate the benefits and the possible side effects. For example, if you have both high blood pressure and migraine, a calcium-channel blocker or beta blocker might be the best choice to treat both. However, if you have asthma, your doctor might not prescribe a beta blocker.
Don't be discouraged if your first choice of preventive medication does not meet your expectations. You and your doctor may need to try three or four different strategies to find the best one for you.
When to call a professional
If you have a history of migraine, you should contact your doctor if you develop headaches that differ from your usual headache or other migraine symptoms. Examples include
- headaches that get worse over time
- new onset of migraine in a person over age 40
- severe headaches that start suddenly (often known as thunderclap headaches)
- headaches that worsen with exercise, sexual intercourse, coughing, or sneezing
- headaches with unusual symptoms such as passing out, loss of vision, or difficulty walking or speaking
- headaches that start after a head injury.
In addition, you may want to see your health care professional if you have headaches that do not get better with over-the-counter medications, severe headaches that interrupt work or the enjoyment of daily activities, or daily headaches.
Prognosis
Most people who develop migraines will continue to have intermittent headaches over many years. However, many people learn to control or to live with their headaches. In addition, migraines often diminish when people reach their 50s or 60s.
Additional info
National Institute of Neurological Disorders and Stroke
https://www.ninds.nih.gov/
National Headache Foundation
https://www.headaches.org/
American Migraine Foundation
https://www.americanmigrainefoundation.org
About the Reviewer
Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing
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