Migraines may be caused by changes in the brainstem and its interactions with the trigeminal nerve, a major pain pathway.
Imbalances in brain chemicals — including serotonin, which helps regulate pain in your nervous system — also may be involved. Researchers are still studying the role of serotonin in migraines.
Serotonin levels drop during migraine attacks. This may cause your trigeminal nerve to release substances called neuropeptides, which travel to your brain's outer covering (meninges). The result is migraine pain. Other neurotransmitters play a role in the pain of migraine, including calcitonin gene-related peptide (CGRP).
A number of factors may trigger migraines, including:
Others have an increased tendency to develop migraines during pregnancy or menopause.
Hormonal medications, such as oral contraceptives and hormone replacement therapy, also may worsen migraines. Some women, however, find their migraines occur less often when taking these medications.
Several factors make you more prone to having migraines, including:
Hormonal changes. If you are a woman who has migraines, you may find that your headaches begin just before or shortly after onset of menstruation.
They may also change during pregnancy or menopause. Migraines generally improve after menopause.
Some women report that migraine attacks begin during pregnancy, or their attacks worsen. For many, the attacks improved or didn't occur during later stages in the pregnancy. Migraines often return during the postpartum period.
One or two days before a migraine, you may notice subtle changes that warn of an upcoming migraine, including:
Aura may occur before or during migraines. Most people experience migraines without aura.
Auras are symptoms of the nervous system. They are usually visual disturbances, such as flashes of light or wavy, zigzag vision.
Sometimes auras can also be touching sensations (sensory), movement (motor) or speech (verbal) disturbances. Your muscles may get weak, or you may feel as though someone is touching you.
Each of these symptoms usually begins gradually, builds up over several minutes and lasts for 20 to 60 minutes. Examples of migraine aura include:
Sometimes, a migraine with aura may be associated with limb weakness (hemiplegic migraine).
A migraine usually lasts from four to 72 hours if untreated. The frequency with which headaches occur varies from person to person. Migraines may be rare, or strike several times a month. During a migraine, you may experience:
The final phase, known as post-drome, occurs after a migraine attack. You may feel drained and washed out, while some people feel elated. For about 24 hours, you may also experience:
When to see a doctor
Migraines are often undiagnosed and untreated. If you regularly experience signs and symptoms of migraine attacks, keep a record of your attacks and how you treated them. Then make an appointment with your doctor to discuss your headaches.
Even if you have a history of headaches, see your doctor if the pattern changes or your headaches suddenly feel different.
See your doctor immediately or go to the emergency room if you have any of the following signs and symptoms, which may indicate a more serious medical problem:
If you have migraines or a family history of migraines, a doctor trained in treating headaches (neurologist) will likely diagnose migraines based on your medical history, symptoms, and a physical and neurological examination.
Your doctor may also recommend more tests to rule out other possible causes for your pain if your condition is unusual, complex or suddenly becomes severe.
MRI scans help doctors diagnose tumors, strokes, bleeding in the brain, infections, and other brain and nervous system (neurological) conditions.
In this procedure, a thin needle is inserted between two vertebrae in the lower back to remove a sample of cerebrospinal fluid for analysis in a lab.
Migraine treatments can help stop symptoms and prevent future attacks.
Many medications have been designed to treat migraines. Some drugs often used to treat other conditions also may help relieve or prevent migraines. Medications used to combat migraines fall into two broad categories:
Your treatment strategy depends on the frequency and severity of your headaches, the degree of disability your headaches cause, and your other medical conditions.
Some medications aren't recommended if you're pregnant or breast-feeding. Some medications aren't given to children. Your doctor can help find the right medication for you.
Take pain-relieving drugs as soon as you experience signs or symptoms of a migraine for the best results. It may help if you rest or sleep in a dark room after taking them. Medications include:
Acetaminophen (Tylenol, others), also may help relieve mild migraines in some people.
Drugs marketed specifically for migraines, such as the combination of acetaminophen, aspirin and caffeine (Excedrin Migraine), also may ease moderate migraine pain. They aren't effective alone for severe migraines.
If taken too often or for long periods of time, these medications can lead to ulcers, gastrointestinal bleeding and medication-overuse headaches.
The prescription pain reliever indomethacin may help thwart a migraine and is available in suppository form, which may be helpful if you're nauseated.
Triptans effectively relieve the pain and other symptoms that are associated with migraines. They are available in pill, nasal spray and injection form.
Triptan medications include sumatriptan (Imitrex), rizatriptan (Maxalt), almotriptan (Axert), naratriptan (Amerge), zolmitriptan (Zomig), frovatriptan (Frova) and eletriptan (Relpax).
Side effects of triptans include reactions at the injection site, nausea, dizziness, drowsiness and muscle weakness. They aren't recommended for people at risk of strokes and heart attacks.
A single-tablet combination of sumatriptan and naproxen sodium (Treximet) has proved to be more effective in relieving migraine symptoms than either medication on its own.
Ergotamine may worsen nausea and vomiting related to your migraines, and it may also lead to medication-overuse headaches.
Dihydroergotamine (D.H.E. 45, Migranal) is an ergot derivative that is more effective and has fewer side effects than ergotamine. It's also less likely to lead to medication-overuse headaches. It's available as a nasal spray and in injection form.
You may be a candidate for preventive therapy if:
Preventive medications can reduce the frequency, severity and length of migraines and may increase the effectiveness of symptom-relieving medicines used during migraine attacks. It may take several weeks to see improvements in your symptoms.
Your doctor may recommend daily preventive medications, or only when a predictable trigger, such as menstruation, is approaching.
Preventive medications don't always stop headaches completely, and some drugs cause serious side effects. If you have had good results from preventive medicine and your migraines are well-controlled, your doctor may recommend tapering off the medication to see if your migraines return without it.
Preventive migraine medications include:
The beta blockers propranolol (Inderal LA, Innopran XL, others), metoprolol tartrate (Lopressor) and timolol (Betimol) have proved effective for preventing migraines. Other beta blockers are sometimes used for the treatment of migraine. You may not notice improvement in symptoms for several weeks after taking these medications.
If you are older than age 60, use tobacco, or have certain heart or blood vessel conditions, your doctor may recommend a different type of medication.
Another class of cardiovascular medications (calcium channel blockers) used to treat high blood pressure also may be helpful in preventing migraines and relieving symptoms. Verapamil (Calan, Verelan, others) is a calcium channel blocker that may help prevent migraines with aura.
In addition, the angiotensin-converting enzyme inhibitor lisinopril (Zestril) may be useful in reducing the length and severity of migraines.
Tricyclic antidepressants may reduce the frequency of migraines by affecting the level of serotonin and other brain chemicals. Amitriptyline is the only tricyclic antidepressant proved to effectively prevent migraines. Other tricyclic antidepressants are sometimes used because they may have fewer side effects than amitriptyline.
These medications can cause sleepiness, dry mouth, constipation, weight gain and other side effects.
SSRIs haven't been proved to be effective for migraine prevention. These drugs may even worsen or trigger headaches.
However, research suggests that one serotonin and norepinephrine reuptake inhibitor, venlafaxine (Effexor XR), may be helpful in preventing migraines.
In high doses, however, these anti-seizure drugs may cause side effects. Valproate may cause nausea, tremor, weight gain, hair loss and dizziness. Don't use valproate if you are pregnant or may become pregnant.
Topiramate may cause diarrhea, nausea, weight loss, memory difficulties and concentration problems.
During this procedure, onabotulinumtoxinA is injected into the muscles of the forehead and neck. When this is effective, the treatment usually needs to be repeated every 12 weeks.
Until recently, experts recommended avoiding common migraine triggers. Some triggers can't be avoided, and avoidance isn't always effective. But some of these lifestyle changes and coping strategies may help you reduce the number and severity of your migraines: