Migraine is the third most common disease in the world. It costs American employers $20 billion each year, and considering how widespread and the suffering it causes are, it’s safe to say research funding is meager at best. The National Institutes of Health provides the mainstay of medical funding in the United States, about $20 million annually — but funding should be 12-fold higher if it will be comparable to research dollars allotted for other brain diseases such as schizophrenia.

A ‘typical’ migraine headache is severe: One-sided, pulsing or throbbing, accompanied by severe pain and discomfort to normal lights, sounds, or smells, not to mention nausea and vomiting. It typically lasts four to 72 hours, during which the scalp can be extremely sensitive to the touch. So it’s not unusual for migraine sufferers — also known as migraineurs — to  withdraw from the outside world to lie down without moving in a dark, quiet room. But the truth is, the realities of life often prevent this form of relief.

The fundamental causes of migraine is not known and likely are complex. The most accepted theory postulates an imbalance of nerve and blood vessel interactions in the head, though this does not explain the cause. We have evidence that altered regulation of brain sodium may be at least part of a common molecular pathway, and are investigating how to stabilize sodium fluxes in a way that may help alleviate the suffering of migraine.

But until then, familiarizing yourself with migraine causes, symptoms, and treatment can help you identify the problem, and then hopefully start feeling some relief. Here’s everything you need to know.

Triggers

Often migraine sufferers can identify triggers that that suggest a migraine onset is likely to follow. The most common trigger is stress, followed by missing meals or sleep, dehydration, or hormonal changes, especially in females around the menstrual cycle. Many other triggers may initiate migraine in some people but not others, and the onset of migraine is more likely when multiple triggers combine, such as stress with missed meals and lack of sleep. And these days, isn’t that everyone?

Types

The most common episodic migraine types are migraine with aura (about 75 percent of patients) and migraine without aura (about 25 percent of patients). But it is uncommon for someone to have migraine with aura exclusively; usually attacks are migraine without aura, with occasional episodes with aura. Migraine is about three times more common in females, almost always runs in the family, and it affects over 35 million Americans. Migraine becomes more common at puberty, peaks around 30-40 years of age, and usually (hopefully) decreases thereafter. And in one study, researchers found that migraine was more frequent with lower household income.

Symptoms

With or without aura, the painful migraine symptoms are similar. Aura is usually a short episode of altered vision of around 15-minutes duration, that moves slowly in the field of view, making it hard to see and drive. After the visual symptoms disappear, severe migraine comes on after about 10 minutes. The aura less commonly affects speech, hearing, skin sensation, or muscle power, but these symptoms are also short-lived and all warn of an upcoming migraine, hence the term aura or warning.

These types of aura can occur in other conditions. Visual aura in older people is quite common unrelated to migraine, without any subsequent headache, and often without any previous migraine history as experienced by both co-authors. Without any warning or knowledge, this can be alarming, but is considered a benign event of aging, and is usually not a warning of stroke or other “doom”.

Other presentations of migraine include altered balance or dizzy spells that last for some hours to days. These may be accompanied by migraine symptoms, but can occur alone, referred to as ‘vestibular migraine’. Many other episodic conditions — co-morbid conditions — occur more commonly in sufferers of migraine, which suggests they share an underlying mechanism (unknown as yet). Migraine comorbidities include anxiety (often with panic attacks), depression, irritable bowel syndrome, gastroparesis (stomach not emptying well), painful bladder syndrome, asthma, allergies, and fibromyalgia. Two conditions that are usually recognized as benign heart murmurs in childhood are also comorbid with migraine: patent foramen ovale (the common “hole in the heart”) and mitral valve prolapse.

Other less common forms of migraine “variants” include cluster headaches (very severe, short duration headaches that are clustered over a short time period ), and migraine with other “autonomic" changes that might be misinterpreted as sinus headache, eye infections, etc. A “retinal” migraine is much less common and is more often a feature of aura generated by the brain, not the retina.

Around three to five million Americans have chronic daily headache (CDH). These include people with migraine episodes that become more frequent until there is daily headache, with fluctuating severity. A severe headache that starts one day but never disappears is called New Daily Persistent Headache or NDPH. CDH is generally the most resistant of severe headache disorders to treat. Severe headache, whether of a migraine type or not, can start after head injury, called post-traumatic headache (PTH). PTH is among the most common disorders in civilian and military populations, follows even mild head trauma, and is often accompanied by other disabling symptoms.

Diagnosis and Treatment

Surprisingly, the medical literature tells us that a third of those with migraine do not know they have it. This seems remarkable given that those of us without migraine cannot imagine not seeking diagnosis for such a disabling condition, yet this informs us of the magnitude of the lack of education and care for this condition, perhaps worry about job status or stigmatization. Diagnosis is best made by a physician. In the current health care system in the U.S. when the time for patient interviews are compressed, a complex history of migraine may not be easily elicited and diagnosed. To explore concerns about migraine diagnosis and treatment, we suggest that a physician with headache expertise be sought.

A headache diary that simply records daily headache symptoms, length of symptoms, treatment attempts and responses can help identify triggers or patterns of migraine that may help both patient and physician to monitor treatment. Comprehensive treatment starts with a detailed diagnostic work-up, then lifestyle modifications to reduce the chances of migraine such as learning what is helpful vs. harmful and making behavioral changes.

Relaxation and alternative medicine approaches are among the most overall effective forms of treatment. Medications fall into rescue or prophylactic approaches. Rescue is self-explanatory and includes non-steroidal anti-inflammatory agents (NSAIDS such as ibuprofen) and more selective migraine compounds (triptans). Prophylaxis usually takes the form of daily medication to reduce the frequency and severity of migraine, and includes drugs developed for treating other conditions that can also help reduce migraine frequency, such as antihypertensives (including beta blockers), antidepressants (including amitriptyline), muscle relaxants (including onabotulinumtoxinA toxin), and anti-convulsants (including topiramate). Countless different medications may help some people, but predicting efficacy is hard and requires trials, dosage adjustment, and avoiding drug interactions.

Though finding the best regimen takes time and patience, careful monitoring of responses to different regimens is worth the effort. It is also important to note that initially effective medications often wear out their efficacy over time. Narcotic compounds, like codeine, hydrocodone, Vicodin, and Percocet should generally not be used for migraine therapy.

Taking a few doses of a rescue medication is perfectly reasonable and often a successful treatment choice for migraine, especially if taken early in the attack. But, unlike for many other painful conditions, more frequent doses can do more harm than good, leading to what is called medication overuse headache (MOH). It is important to avoid MOH, and a common rule of thumb is to take no more than five consecutive doses within two to five days before taking a break. If need for rescue is more common than that, it is important to get a physician’s help.

Because of the frequency of comorbid conditions, the comprehensive and integrated treatment of comorbidities is important. Symptoms may involve different specialists, including psychiatrist, gastroenterologist, gynecologist, urologist, internist, etc. A good treatment for one comorbid condition can help the others, yet negative interactions may worsen migraine. This complexity means the migraineur needs to coordinate and navigate their health care system!

Recognizing the needs for better treatment, especially for CDH, there is substantial ongoing effort by the pharmaceutical, clinical, and research communities. The current most promising approaches in the pipeline are Phase 3 trials of antibodies against a peptide called CGRP, which may lead to new treatment options in the near future.

Michael Harrington, MB, ChB, FRCP, is the director of neurosciences at Huntington Medical Research Institutes in Pasadena, Calif.