When many people think "migraine" they think only of the pain of migraine. In reality, a migraine episode consists of far more. The typical migraine episode actually consists of four parts, referred to as phases or components. It's important to note that not every migraineur experiences all four phases. Also, episodes can vary with different phases experienced during different episodes. The four phases of a migraine episode are:
The prodrome (sometimes called "preheadache") may be experienced hours or even days before a migraine episode. The prodrome may be considered to be the migraineur's "yellow light," a warning that a migraine is imminent. For the 30 to 40% of migraineurs that experience prodrome, it can actually be very helpful because, in some cases, it gives opportunity to abort the episode. For migraineurs who experience prodrome, it makes a solid case for keeping a migraine diary and being aware of one's body. Symptoms typical of the prodrome are:
- food cravings
- constipation or diarrhea
- mood changes: depression, irritability, etc.
- muscle stiffness, especially in the neck
- increased frequency of urination
The aura is the most familiar of the phases. Aura follows the prodrome and usually lasts less than an hour. The symptoms and effects of the aura vary widely. Some can be quite terrifying, especially when experienced for the first time. Some of the visual distortions can be exotic and bizarre. It's interesting to note that migraine aura symptoms are thought to have influenced some famous pieces of art and literary works. One of the better know is Lewis Carroll's Alice in Wonderland. While most people probably think of aura as being strictly visual, auras can have a wide range of symptoms, including:
- visual symptoms: flashing lights, wavy lines, spots, partial loss of sight, blurry vision
- olfactory hallucinations (smelling odors that aren't there)
- tingling or numbness of the face or extremities on the side where the headache develops.
- difficult finding words and/or speaking
- partial paralysis
- auditory hallucinations
- decrease in or loss of hearing
- reduced sensation
- hypersensitivity to feel and touch
Approximately 20% of migraineurs experience aura. As with the prodrome, migraine aura, when the migraineur is aware of it, can serve as a warning, and sometimes allows the use of medications to abort the episode before the headache itself begins. As noted earlier, not all migraine episodes include all phases. Although not the majority of episodes, there are some migraine episodes in which migraineurs experience aura but no headache. There are several terms used for this experience, including "silent migraine," "sans-migraine," and "migraine equivalent."