The three most common forms of pain treated in the United States are headache, backache, and metastatic pain or cancer pain.Headaches are a major reason why people miss work or school or visit a healthcare provider.
The most common type, tension headaches, caused by tight muscles in the shoulders, neck, scalp, and jaw, are often related to stress, depression, or anxiety and may occur more often in people who work too much, sleep too little, miss meals, or drink alcoholic beverages.
Migraine headaches, which affect about 12 percent of Americans, involve moderate-to-severe throbbing pain, often on one side of the head. Migraine is diagnosed by its pain and number of attacks (at least five, lasting four to 72 hours if untreated) and additional symptoms including nausea and/or vomiting, or sensitivity to both light and sound.
Migraines are three times more common in women than in men and may relate to changes in hormones and hormonal levels during their menstrual cycle.
On the other hand, people with chronic migraine headaches, an extremely incapacitating collection of neurological symptoms, tend to have recurring attacks triggered by a number of different factors, including stress, anxiety, hormonal changes, bright or flashing lights, lack of food or sleep, and dietary substances.
In a new study, researchers reviewed the role of sex hormones in the activation, modulation, and regulation of the main thermoTRP channels involved in the pathophysiology of migraines. The results suggest that sex hormones affect cells around the trigeminal nerve and connected blood vessels in the head and that estrogens, at their highest levels in women during reproductive years, are particularly important for sensitizing these cells to migraine triggers.
According to Dr. Antonio Ferrer-Montiel from the Universitas Miguel Hernández in Spain, modulation of the trigeminovascular system by sex hormones plays an important role that has not been properly addressed. Ferrer-Montiel and colleagues reviewed decades of literature on sex hormones, migraine sensitivity and cells' responses to migraine triggers to identify the role of specific hormones.
They noted that some, like testosterone, seem to protect against migraines, while others, such as prolactin appear to make migraines worse. These hormones appear to make the cells' ion channels, which control the cells' reactions to outside stimuli, vulnerable to migraine triggers. While some hormones need much more research to determine their role, estrogen appears to be critical in understanding migraine occurrence.
Although estrogen was initially identified as a factor by the greater prevalence of migraine in menstruating women and the association of some types of migraine with period-related changes in hormone levels, evidence now suggests that estrogen and changes in estrogen levels sensitize cells around the trigeminal nerve to stimuli, which may trigger a migraine attack.
However, the researchers conclude that sex hormones may not be the only players in determining sexual dimorphism in migraine pain, as this is a very complex phenomenon involving both gonadal-dependent and independent mechanisms that most likely complement each other in defining sex differences in migraine and chronic pain disorders.
