what causes headache
What Causes Headache and Migraine?
Pain is an important warning sensation. Without pain, there would be no indication that our bodies were in danger of being damaged. In the case of headaches and migraines – migraine is the process by which the symptom of headache (among others) is experienced. Exactly how the migraine process begins is still unclear despite advances in medical imaging. The most current theory is known as “cortical spreading depression” in which abnormal brain chemistry begins a chain of reactions ultimately affecting one’s central nervous system.
It is thought that the brains of migraine sufferers are more sensitive to change and certain conditions than other people who do not experience migraines. When the brain encounters a condition it does not like it reacts by raising an alert. As a migraine sufferer, you brain appears to be more sensitive and reactive to certain conditions.
Your brain’s alert signal causes neurons to become excited and spread across your cortex. The neurons start sending messages using built in nerve pathways such as the trigeminal (located behind the ear on either side of your head and spreads in three directions – up towards your forehead, straight across to your nose, and along your jaw) and upper cervical nerves to blood vessels around the head, face, and neck, causing them to become swollen and irritated.
Chemicals are also released at this time including serotonin (levels rise then fall), dopamine (responsible for changes in mood, nausea, and fatigue,) and norepinephrine. This abnormal flow of chemicals is thought to be caused by a deficiency of magnesium and malfunctioning calcium channels. The nerves surrounding this tissue then communicate back to your brain that there is inflammation. Your brain takes tissue inflammation seriously and as such alerts you via the sensation of pain.
One of the interesting, although unfortunate side effects of the migraine process is the interference with your body’s endorphin production, which would naturally reduce pain. Instead, the pain you feel during a migraine is amplified beyond what you would feel normally. The fact that you feel additionally sensitive during a migraine is not an illusion.
Additionally worth emphasizing a second time is that pain (headache) is really a symptom of the migraine process. Is it possible to have a headache and not a migraine? Yes. Is it possible to have a migraine and not a headache? Yes.
Am I Going Crazy?
Once a migraine gets going one can experience all sorts of unpleasant side effects like nausea, digestive problems, sweating, flushing and chills. This is most likely due to the inflammation of the blood vessels in the membranes lining the brain. Another theory suggested is that the nervous system is affected by the same factors that trigger migraines.
Additionally there are other symptoms which many find especially frightening – primarily visual disturbances (flashing lights, loss of vision, distortions, etc,) numbness, and sometimes even partial paralysis. This leads many people to worry that they may be experiencing a stroke.
The exact cause of these frightening effects is not known for certain, but it is thought to be due to constricted blood vessels, losing blood flow to key area of the brain or senses, and activation of certain nerves like the trigeminal (feelings of numbness) and occipital (sensations of coldness, vibration, trickling, burning, or itching) nerves. It appears that the gradual onset of symptoms could reflect the wave of blood vessel constriction as it moves through your brain.
Constricted blood vessels then lead to a reduction in the flow of blood and neural information to crucial parts of the brain, eyes, and inner ears.
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