Pain is a very subjective experience. In addition, there are many factors that can alleviate or increase it. For example, stress, anxiety and depression increase our perception of pain while holding the hand of a beloved person or meditate reduce it.
However, several studies suggested the idea that women may experience more pain than men. Among them, a research conducted at the University of Stanford, which analyzed around 11,000 clinical records. These researchers found that women tended to report a more intense pain, especially when they were suffering from acute inflammation-related problems.
Various data support this hypothesis, including the fact that many of the chronic pain diseases are more common in women.
Fibromyalgia, for example, is six times more common in women. Headaches are four times more common and migraine is three times more common in women. Women are also twice as likely to have multiple sclerosis, two to three times more likely to develop rheumatoid arthritis and four times more likely to suffer from chronic fatigue syndrome than men. In addition, autoimmune diseases, including debilitating pain, affect women three times more than men.
How pain receptors work?
Why do women feel the pain more intensely? Researchers at the University of Milan think that women may have a different pain threshold than men.
This difference could have a biological cause and be based on the mechanisms involved in regulating the transmission of pain, particularly in the synapses.
The synapses are the connections that allow transmissions of peripheral nervous fibers to those that drive the central nervous system impulse. This process is essential because it is in these neural connections where it is possible to modify the course of the painful stimulus, as with chronic pain processes.
The descending paths modulate the activity of these synapses, which act as a sort of traffic light that transmits impulses. Between the thousands of impulses, only two hundred or maybe a thousand can pass, but it may happen also the opposite, as in the case of chronic pain, and a thousand impulses could be perceived as ten thousand.
This control mechanism also affects the information from the brain area involved in emotional life, the limbic cortex. Therefore, we use to say that pain has an important emotional component. There are specific neural connections between areas that regulate pain and emotional areas of the brain. This means that a problem in emotional life could affect the functioning of downstream pathways and hence the perception of pain.
Pain is an ancient mechanism that warns women of danger
Stress analgesia is a very interesting phenomenon, because in those cases we do not actually perceive pain, even if the wound is severe. It’s common in combat soldiers or fire-fighters in action, who find themselves injured only when they are safe. But it has been found that this phenomenon is more common and intense in men.
For women, stress analgesia appears differently. In fact, estrogen has been shown to play an active role in the natural “analgesic” system in the brain. When the levels of this hormone are high, the brain responds by releasing endorphins to effectively suppress pain signals but when these levels decrease, it increases the perception of pain.
It is also interesting noting that women of childbearing age produce endogenously cannabinoids, naturally occurring analgesic substances that decrease during certain stages of the ovarian cycle, and this results in an increase in pain sensitivity.
These differences in how the brain responds to pain, according to researchers at the University of Milan, may depend on factors related to the conservation of the species. In the past, the role of man was to fight and procure food, so it was important that he resisted pain until the danger had passed. On the contrary, the role of women was more protective, so it is understandable that they have developed more specific natural mechanisms that allow them to feel pain quickly to know when the family is in danger.
This hypothesis makes even more sense with the results of a recent study conducted with guinea pigs at McGill University. In this experiment, it was noticed that sex was involved in transmission in transmission and cessation of pain. In males, the microglia cells play an essential role in transmission and cessation of pain, but in females, T cells are more involved.
Doctors take less seriously female pain
Unfortunately, doctors often take less seriously the pain of women. A study at the University of Maryland in the United States revealed that men expect an average of 49 minutes to receive an analgesic for acute abdominal pain. Women have to wait an average of 65 minutes to receive the same treatment for the same cause. And that’s all because doctors often think that their pain is “emotional”, “psychogenic” or even “unrealistic”.
Another study conducted at the University of Pennsylvania found that women are between 13 and 25% less likely to receive opiate treatment to relieve pain while men are expected to be prescribed this treatment more quickly and more frequently.
Sorge, R. E. et. Al. (2015) Different immune cells mediate mechanical pain hypersensitivity in male and female mice. Nature Neuroscience; 18: 1081–1083.
Fornasari, D. (2012) Pain Mechanisms in Patients with Chronic Pain. Clinical Drug Investigation; 32(1): 45-52.
Ruau, D. et. Al. (2012) Sex Differences in Reported Pain Across 11,000 Patients Captured in Electronic Medical Records. J Pain; 13(3): 228–234.
Chen, E. H. et. Al. (2008) Gender disparity in analgesic treatment of emergency department patients with acute abdominal pain. Acad Emerg Med; 15(5):414-418.
Hoffmann, D. E. & Tarzian, A. J. (2001) The girl who cried pain: a bias against women in the treatment of pain. J Law Med Ethics; 29(1): 13-27.