What Are Migraines And What Causes Them?

What's a migraine and it's causes

Migraines are the third most common disease in the world, after dental caries; it is the seventh highest cause of disability worldwide and shows no discrimination for class, race or economic background. 18% of American women and 6.5% of American men suffer from them, half of whom aren’t diagnosed or treated for it. Nearly one in six people worldwide suffer from them, 2.9% of all years of life lost to disability are caused by migraines. And these are probably underestimated.

Yet migraines are never in the news, they aren’t ranked particularly highly on the lists of diseases that need cures or causes of poverty. They are amongst the most debilitating non-life threatening conditions humanity can suffer from but they get almost no attention. It is as if having a bad headache doesn’t count as an acceptable disease, deserving of attention. Sufferers of migraines know differently.

A Little History of Migraines

Those symptoms should be immediately familiar to anyone who’s ever had a migraine, and that was 2,500 years ago. They have been consistently described in medicine ever since. The problem is that nobody understood what they were or what caused them.

This view didn’t change very much until the 17th century when slightly less inaccurate theories were put forward. Blockages in blood vessels or blood vessels were found in some migraine patients when they underwent an autopsy, and this was linked, not unreasonably, with their condition. The descriptions of what migraines are became more accurate but they didn’t have the technology to explore the causes.

It wasn’t until the Twentieth and Twenty-First centuries that an at least vaguely accurate description of what causes migraines came about. But first:

What is a Migraine?

One of the world’s leading experts in migraines cannot describe a migraine in anything but broad terms. This is the unfortunate relic of a word thought to describe one condition turning out to contain many different conditions. Perhaps as many conditions as there are sufferers.

The topic of migraines is a complex one. The main symptom for many people is a painful headache; a vision that is disturbed; sometimes accompanied by sensitivity to light, smells and sound; vomiting and nausea. Each a migraine is different, with different symptoms appearing in different migraines and varying in the frequency and length of time they occur for. Most people have no noticeable symptoms between the onset of migraines and when they do suffer from an attack, they generally last between 4 and 72 hours.

Overstating the debilitating nature of migraines is difficult. During an attack, the sufferer will be incapable of work or play, even of talking for some. If an attempt is made to push through the symptoms, they are often made worse and extend the length of a migraine, according to some sufferers. Appointments are missed, work is canceled or delayed, children are left to fend for themselves or given to relatives for the duration.

The majority of sufferers fall into two categories: migraines with auras and migraines without.

Migraine with Aura

A migraine with an aura can have most or all of the symptoms of a migraine without an aura but also suffer from the addition of visual and sensory disturbances. These symptoms usually occur before the onset of a headache but can occur on their own without the accompanying pain. Up to 30% of migraine sufferers encounter the symptoms of aura. Attacks can occur several times in a year or less often.

The symptoms develop typically over a 5 to 20 minute period and rarely last longer than an hour.

The visual symptoms of a migraine with aura include:

  • Colored spots
  • Stars or sparkling lights
  • Flashing or strobing lights
  • Zig-zag lines
  • Temporary loss of vision
  • Blind spots in your field of vision
  • Tunnel vision

The non-visual symptoms of a migraine with aura include:

  • Pins and needles in the extremities
  • Dizzy spells
  • Vertigo
  • Loss of strength (usually on one side)
  • Numbness
  • Tingling

Causes of Aura in Migraines

Like all forms of a migraine, the causes of aura in a migraine are not well understood. When migraine patients are brain scanned there appears to be a common feature called a “cortical spreading depression”, or CSD. This is when activity in certain parts of the brain are depressed for a period. This CSD is transient, it can move, perhaps causing the shifting visual and physical phenomena that characterize aura.

This was discovered in 1944 and little appears to have been advance since.

Other Forms of Migraine with Aura

Migraine with brainstem aura, hemiplegic migraine, and retinal migraines all fall under the term migraine with aura as they all produce visual phenomena.

Migraine with Brainstem Aura

This is a rare type of a migraine and knowledge is limited as to its causes. It is typically characterised by slurred speech, problems with hearing, tingling sensations in the extremities, vertigo, tinnitus, dizziness and disturbances (aura) in the visual plane of both eyes.

These symptoms generally occur and recede before the onset of a headache, but can occur without. Brainstem aura migraines makeup about 10% of the visual aura migraine sufferers and are often in adolescence.

The causes of a migraine with brainstem aura are not well understood, but there does appear to be a “spreading depression” of cortical activity that occurs in the brainstem (where the spine connects to the brain and above) and in the cerebral cortex (the outer surface of the brain) simultaneously. Because patients with this form of a migraine are rare there hasn’t been much study of the causes and treatment.

Hemiplegic Migraine

Hemiplegic means weakness or paralysis on one side of the body. Hemiplegic migraines can be characterized as a typical visual migraine with aura but also with the presence of temporary paralysis. Paralysis can occur in the face or limbs and is often accompanied by pins and needles or numbness. As with a migraine with aura, there can be difficulties with speech and vision, the patient can also become confused.

There are two subtypes of hemiplegic migraines, familial and sporadic. Familial chemical agent migraine is when two or more individuals in the same family develop a hemiplegic migraine. If a parent suffers from hemiplegic migraine, their offspring have a 50% chance of developing the same condition.


Genetic studies have isolated at least three genes that are potentially connected with familial hemiplegic migraine. There appear to be issues with calcium channel proteins for some families. For others, there is a channel involved in cell metabolism or in sodium channels. These mutations all occur on different chromosomes. The picture as to why familial hemiplegic migraines occur is anything but clear as many cases of familial hemiplegic migraine do not have mutations that are known.


Sporadic hemiplegic migraine is the same as a familial hemiplegic migraine but without the family history. This is potentially due to the mutations that cause a hemiplegic migraine arising in the individual during their zygote or fetal stage, or to some unknown outside factor.

Migraine without Aura

Previously known as a typical migraine or hemicrania simplex, migraine without aura generally last between 4 and 72 hours without treatment and are the form of a migraine for between 70% and 90% of those who suffer from migraines.

Headaches are usually hemispherical e located, or on one side of the head and are generally a throbbing or pulsing sensation that can be very painful. Many migraine sufferers also report sensitivity to light, or photophobia, alongside sensitivity to sound, phonophobia. Normal social activities are not possible for most people who suffer from a migraine without aura as the symptoms are too debilitating. Symptoms can also include nausea vomiting or diarrhea.

Some unfortunate sufferers can experience several attacks of a migraine without aura in a week. For others, it can be as frequent as once a year. Currency and severity of a migraine can make a massive impact on the quality of life that somebody can attain. Two or three attacks of migraine a week can make holding down a job impossible, having an active social life very difficult, and even things like caring for children or housework can be impossible.

The Social and Economic Cost of Migraine

With a migraine affecting almost one in six women across the world, and his many men, it is difficult to communicate the cost both socially and economically of a migraine. While migraines do not reduce people’s life expectancies, the quality of life is often substandard. The economic cost of a migraine is not studied at all well, it is clear that by taking millions of men and women out of economic production, we not only lose their production but the debilitating nature of a migraine means that they are a burden to others as well.

This burden is one of the most significant costs to society of a migraine. It is also costly to the individual to have to rely on others when they are otherwise capable. It compounds the pain and suffering to place yourself in a position of need.

Causes of Migraines

Causes for migraines are not at all understood. We know that there are familial links, and genetics studies have strengthened this case. The evidence is indistinct, however, as some people with the genes that are a migraine related do not develop migraines, and not everybody in a family develops them.

The brain has over 90 billion neurons in it, each with an average of 10,000 connections between them. The vast complexity of human brain makes any solid conclusion very difficult, and as a migraine is still a relatively understudied and ignored subject, it will be years before any real conclusions can be drawn as to the causes.

There are ongoing studies into a migraine, and the advent of MRI scanners has increased the amount that is known about both the functioning of the brain and diseases that affect it. With the increased resolution of modern MRI scanners, it should be possible to watch a migraine happened in real time and in high detail soon. This should give vital clues as to the causes and potential treatments of migraines.

Policymakers around the world do not take a migraine as seriously as perhaps they should. Because it is so understudied and regarded as more a fact of life than a debilitating condition, the data needed to persuade politicians and business people to expand research and treatment for migraine sufferers is not there. The situation looks unlikely to change any time soon.

Triggers for Migraine

Because conditions in the brain cause migraines, the psychological and physiological causes of a migraine are interconnected. You cannot look at a migraine in isolation from the emotional and physical state of a person, because all of the conditions that are required for a migraine appear to be influenced by the surrounding conditions of the brain.

Emotional Triggers

The emotions of an individual influence the likelihood of an attack very strongly. Triggers can include:

  • Stress
  • Anger
  • Emotional arousal
  • Shock
  • Anxiety
  • Anticipation

Generally, people who can control their emotions also find that they can reduce the likelihood of a migraine attack in the future. Unfortunately, as migraines are distressing and painful experiences, it is difficult to remain emotionally calm if you are anticipating an attack. No matter how controlled somebody’s emotions might be, the stress of work, children, a bereavement, planning something, having a migraine that means that the sufferer cannot engage with the activity as mentioned above.

Physical Triggers

The brain is intimately linked with the body, it is the same. So it, therefore, makes sense that a physical condition in the body, much like the physical conditions created by emotions, can cause a migraine. These triggers can include:

  • A poor night’s sleep
  • Exhaustion
  • An irregular sleep pattern
  • Muscle tension
  • Squinting or eye strain
  • Physical exercise
  • Grinding teeth
  • Smoking
  • Medication

Due to the sensitivity of some people to physical triggers, some activities are impossible for them. For some, sports are off limits, for others watching television or going to the cinema.

Environmental Triggers

Visual stimuli, in particular, are common causes of a migraine, which has led some to link with some forms of epilepsy. Environmental triggers include:

  • Bright or flashing lights
  • Intense aromas
  • Loud or high pitched noises
  • Fumes

The sensitivity of subsidies environmental triggers means they cannot venture outside without sunglasses or indeed at all. The random soundscape of the modern world can provide many triggers for sufferers and this can reduce the social and economic interactions they are capable of without suffering an attack.

Dietary Triggers

It is well established that there is a link between diet and mental health, it should be no surprise that somebody’s diet can trigger migraines. Brain-like neurons surround the gut in what is known as the enteric nervous system. This is parasympathetic with the brain and is being discovered to play a significant role in the regulation of brain conditions. What we eat affects us and triggers migraines in some. There is some evidence to show that craving a specific food can warn of an oncoming migraine.

  • Not enough food
  • Dehydration
  • Caffeine
  • Alcohol
  • Food additives like aspartame, nitrates and MSG
  • Specific foods such as cheese, fruits or chocolate

Treatment for Migraine

Lying down in a darkened, quiet room is helpful to many, as is sleeping, though no many sufferers can manage to get to sleep with a migraine. Vomiting can cause the symptoms to retreat for some, for others, it is merely a disgusting necessity.

Medication is generally the only successful form of treatment for a migraine. There are a vast number of different medications available, however, there are not many does that successful. Each a migraine is a different experience and each person experiences them differently. The differences in causes and symptoms of a migraine result in many medications not working for many different people.

Off the shelf medication such as paracetamol and ibuprofen work for many but if the symptoms are severe and are lasting a long time, stronger pain relief is needed. On prescription is available a drug called triptans, developed as a migraine treatment. This can be very successful for some but as with all drugs that affect the brain, they can have side effects that make them not worth bothering with. Consult with your doctor about the appropriate course of action to take.

When taking medications, always read the instructions in the packet or on the box and never exceed the limit that they state. Even common painkillers such as aspirin, ibuprofen, and paracetamol can be deadly if taken in excess or by someone with an allergic reaction to them. When you start and stop taking a drug, you should do this in consultation with your doctor.

Referral to a specialist migraine clinic may be necessary if conventional treatments aren’t working.


There are potent drugs that can help reduce the frequency of attacks. These should only be taken on a doctor’s recommendation as they can have very severe side effects. Preventative medications include beta blockers, antidepressants such as amitriptyline, epilepsy drugs such as topiramate. These can have potentially severe effects on a person so should only be taken as a last resort.

There is some evidence to show that acupuncture has a frequency reducing the effect on migraines, though how this happens is not understood at all. Vitamin supplements are beneficial but again, the evidence is shaky.

Experimental work into transcranial magnetic stimulation and nerve stimulation is ongoing and is promising. These treatments should only be administered by experts and only on the advice of your doctor.

Behavioural Prevention

Avoiding triggers is one of the best ways of reducing the frequency of migraine attacks. Unfortunately, due to the sensitivity of some, this can mean avoiding everyday activities like going to the supermarket, driving or attending concerts.

For many, however, a pair of sunglasses or earplugs at the right time can turn what would have been an attack into just another stimuli. Being fit helps reduce the chance of physical exhaustion causing a migraine as the base level for a trigger will be much higher. Anticipating when and where attacks occur can be very helpful. Many people keep a diary to establish links between foods, visual stimuli or other factors in their attacks.

Seeking Help

Migraines are very common so a GP or physician will be able to make a diagnosis and advise with treatment fairly easily. There is a lot of support available and a great deal of information on the internet. Be wary of “miracle cures” or fad diets, they have little or no evidence base and could result in a nasty migraine attack. Another up and coming treatment that shows promise is CBD oil, this all-natural remedy has indicated that it may be capable of treating the pain of a migraine and reducing the frequency of attacks.

If in doubt, talk to your doctor. Consulting with a doctor will always be very much helpful for you.

Editorial Staff
Editorial Staff
At cannabisMD we aim to provide you with all the information and knowledge you need to take the next step in your personal cannabis journey! Read about our team

Leave a Reply

Your email address will not be published. Required fields are marked *