Types and Causes of Headaches

Headaches can be caused by a large variety of reasons. Those suffering from regular headaches are often aware of the cause of their headache, however, in many cases, the cause of a headache may go unknown.

There are two basic categories of headaches, namely primary and secondary. Primary headaches are those headaches that are caused for no specific underlying reason.  They are not the result of any specific disease or process and are commonly thought of as being a result of a problem in brain function rather than a problem with the brain’s basic structure itself.  Primary headaches include migraine & cluster headaches as well as tension-type headaches. Being that there is no underlying brain structural problem with primary headaches, it is important to note that there are no investigative tests such as magnetic resonance imaging tests (MRIs) or computed tomography (CT) scans that can be done to determine an exact reason for the headache. If you suffer from primary headaches, however, some investigative tests may still be used to rule out other causes of your headaches.

Secondary headaches result from another problem, which has a headache as a symptom of the underlying initial problem. Secondary headaches can result from a huge variety of problems including head and neck injuries, inflammatory processes within the body, hormonal issues, as well as more serious causes such as brain tumors or aneurysms.

The main types of primary headaches and some common secondary types of headaches are described in detail below:

Migraines

Migraines are often described as a severe (and often unbearable) throbbing or pulsating pain in one or both sides of the head, often around the temples, front of the head, or behind an eye. Approximately 15-20% of migraine headaches are accompanied by a sensory aura, which is a particular sensation that, in adults, precedes the actual headache pain (children sometimes get the aura at the same time as the headache). An aura can present in the form of a variety of sensations such as suddenly smelling a certain smell, seeing spots or zigzags, feeling a twitch, excessive yawning, numbness or tingling in the face or one part of the body, or even weakness on one side of the body. Some migraine sufferers even crave certain foods, such as chocolate, as their aura.

Nausea, vomiting, double vision, and extreme sensitivity to light, sound or smells often accompany migraines. Migraines can also be accompanied by a loss in memory, altered thinking capacity, and altered speech.  Migraines can last anywhere from an hour to, in extreme cases, several days.  Most migraines are severe enough that they cannot be ‘worked through’ and once the headache has passed a ‘headache hangover’ is often felt, which is a feeling of extreme fatigue, dizziness and difficulty concentrating. Neck pain may or may not be present during or after a migraine headache.

Migraine headaches are often familial, meaning that they run in one’s family.  Being depressed can also increase your likelihood of suffering a migraine headache, as can lack restorative sleep or having chronic sinus problems. Migraines are more common in women than in men.

Migraine headache triggers are not always known but some common food and drinks that may trigger migraines include certain red wines, cheeses, chocolate, excessive caffeine, pickled foods, foods containing monosodium glutamate (MSG), citrus fruits, and sourdough bread.   Other common non-food-related triggers include flickering lights, intense exercise, intense smells (such as perfume), weather changes (barometric changes), and menstruation cycles.  Stress is an extremely common trigger of migraine headaches in many sufferers.

The physiology of migraines is still being studied however it is accepted that there is an increased sensitivity in the brain to certain environmental triggers which then sets off a chemical chain of events in the brain. The migraine trigger causes a chemical release in the brain, which in turn affects the blood vessels of the brain, causing them to swell and release further chemicals.  The chemicals released to act as an irritant to the pain structures in the head and face including the trigeminal nerve and the area that it supplies, hence causing the headache.  Altered levels of serotonin, which is an important brain chemical that regulates pain and mood, have also been associated with migraines. It has also been shown that during a migraine headache there is an altered blood flow to certain parts of the brain’s cortex such as the occipital (visual) cortex.