There is no general consensus as to what causes fibromyalgia. Many doctors speculate that there isn’t a single cause to the disorder but that it involves several different physical and emotional factors that work together to cause the disease.

These are some things that may be related to who gets fibromyalgia and who does not:

• Genetic factors. There may be some yet unknown genetic reasons why some people get fibromyalgia and others do not. It is known to run in families although it does not appear that there is a single gene involved in getting fibromyalgia. Genetic mutations have not yet been discovered but may play a role in developing the disease. According to the National Institute of Arthritis, Musculoskeletal, and Skin diseases, there may be genes in the human genome that regulate the ways the body handles pain. Those who have fibromyalgia may have inherited genes that result in an exaggerated response to pain in situations that another individual would not find painful.
• Fibromyalgia occurs to a much greater degree in women when compared to men. There may be something about female hormones that trigger the disease in women but not in men. The hormonal milieu in women is much different in women than it is in men and the presence of female hormones may affect the nerves in such a way as to make fibromyalgia more likely.
• Certain infections. Because fibromyalgia can develop following an infection, it has been speculated that certain types of infections make fibromyalgia worse or trigger the onset of the disease in susceptible individuals.
• Emotional Trauma. People with post-traumatic stress disorder from childhood or other types of trauma are at a greater risk of developing fibromyalgia. Exactly how psychic trauma can lead to the physical manifestations of fibromyalgia is not yet clear.
• People who experience greater levels of stress in their lives have a greater incidence of fibromyalgia. Whether it is from a single stressor or multiple stressors over the course of a lifetime that contributes to fibromyalgia is not yet clear.
• Brain chemicals. Some researchers are looking into the idea that low levels of serotonin and other brain neurotransmitters affect the way the brain responds to pain. Additionally, there may be increased levels of substance P, the neurochemical that results in the sensation of pain. Finally, there may be lower levels of endogenous endorphins, the brain chemicals that protect us from the experience of pain, in patients suffering from fibromyalgia.
• Trauma to the brain and spinal cord. Some research has pointed to the idea that a sudden trauma to the spinal cord and brain trigger a decreased ability to respond to pain sensations in a normal way.
• Sleep difficulties. People with fibromyalgia commonly suffer from disorders of sleep. Whether the sleep problems cause the fibromyalgia or are the result of fibromyalgia is not yet clear. Poor sleep habits have been known to alter the levels of certain brain chemicals that contribute to fibromyalgia.