The exact cause of migraine is not fully understood. For a long time, the generally accepted theory was that migraine and its symptoms were caused by problems in the blood vessels of the head. Recent research, however, has shown that, while blood vessel constriction can result in pain, the cause of migraine, itself, is likely rooted in a disorder of the central nervous system.

What’s Causing my Migraine?

The chain of physical and chemical events in and around the brain that leads to migraine headaches is still unclear. What is known is that something activates a cascade of biochemical reactions that may trigger an inflammatory response and overexcitement of the trigeminal nerve, a major pain pathway which controls sensation in the face and head. This overexcitement spreads to other nerves in the meninges—the protective membrane covering the brain—and leads to pain and other migraine symptoms.

Migraine Factors

Research to understand the details of this process is ongoing, but the following are suspected as important factors in causing migraine headaches:

  • low levels of serotonin—a neurotransmitter that controls mood, sleep, and appetite—that cause painful blood vessel constriction
  • dietary deficiency in magnesium, a mineral that is important for nerve function
  • neuropeptides—small protein-like molecules—that trigger inflammation and cause pain receptors to activate  
  • abnormalities in the way cells transport calcium ions, which are used in transmitting nerve signals
  • the release of nitric oxide—a chemical that signals blood vessels to dilate—by overactive neurons
  • hormonal fluctuations, especially of estrogen in women
  • inflammation of the maxillary nerve, a branch of the trigeminal nerve that runs behind the cheekbone and controls sensation in the mouth and nose

Migraine Triggers

Although the specifics of migraine neurobiology are unknown, there are many factors known to make migraine headaches more likely to occur. Each patient's triggers may be different, but most fall into the following categories:

  • Changes in emotional stress levels. Increased stress at home or at work can trigger a headache, as can a reduction in stress, such as finishing an important project or going on vacation.
  • Certain foods and chemicals, including chocolate, alcohol, nuts, monosodium glutamate (MSG), aged cheeses, processed meats such as hot dogs or cold cuts, high levels of caffeine, and aspartame (the artificial sweetener in Equal and NutraSweet)
  • Hunger or dehydration, especially when caused by a skipped meal
  • Changing weather conditions, including barometric pressure, humidity, and temperature
  • Changes to sleep patterns, whether getting more or less sleep than normal
  • Bright lights, such as direct sunlight without sunglasses or light emitted from a movie screen
  • Loud sounds, such as construction equipment or a concert
  • Strong odors, such as excessive perfume, cologne, or air freshener
  • Intense physical activity including exercise, lifting heavy objects, or sexual activity
  • Hormonal changes in women, whether related to menstrual period, pregnancy, birth control pills, or hormone replacement therapy for menopause
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Break It Down: Migraine and Severe Migraine

Migraines are intense headaches that affect more than one in 10 people. Women are three times more likely to experience migraines than are men, and migraines have been shown to run in families.

These painful headaches can last up to 3 days if not treated, causing throbbing pain, sensitivity to light or sound, nausea and vomiting, and difficulty doing normal physical activities, such as standing or walking. Severe migraines can also cause symptoms like uncomfortable tingling or weakness in your arms and legs, or even vision changes such as seeing flashing lights or blurring. Vision changes, odd sensations of smell, or feeling unwell may precede a migraine in what is known as the aura. Auras typically begin slowly over five to 20 minutes and usually cease within 60 minutes.

While rare, other types of migraines can cause partial blindness, double vision, paralysis on one side of the body, vertigo, or symptoms that may mimic a stroke. Migraines can become so severe and disruptive that they require treatment in the emergency department. If you experience speech, vision, or balance problems you haven’t experienced before, you should be seen by a qualified medical professional. Persons over the age of 50 should seek medical attention if what appears to be a migraine starts suddenly, like a clap of thunder, because this presentation could be a sign of something more serious.

You should know that certain factors can trigger migraines. These include physical or emotional stress, bright lights and sounds, strong odors, changes in the weather, cigarette smoking, drinking alcohol, not getting enough sleep or food, and certain foods and food additives. Women experiencing hormone changes during menopause may also begin to experience migraines for the first time.

If you begin to experience a severe migraine, resting in a quiet, dark room might help. Several over-the-counter medicines, such as ibuprofen or naproxen, may help relieve the symptoms and severity of migraines.

Your doctor may prescribe special medications to treat migraines. Triptans comprise the class of drugs most commonly prescribed for severe migraines. Other types of medications, including antidepressants, cardiovascular drugs, and anti-seizure medications, have been approved to help treat and prevent migraine headaches.

Avoiding known triggers is a logical way to avoid migraines. Other ways to help prevent them include getting adequate sleep, relaxing to relieve stress, and using acupuncture or massage therapy.

Keeping a diary of your headaches, noting events that lead up to them and their severity, and bringing it to your doctor’s appointment can offer clues about how best to treat your migraines.