The exact cause of fibromyalgia is unknown, and research into the cause is ongoing. However, research into fibromyalgia has identified a number of possible causes of the condition, and these are outlined below.

Problems with pain messages

One of the most likely causes of fibromyalgia is a problem with the way that pain messages are carried and received in your body.

It is thought that in people with fibromyalgia, the central nervous system (which transmits messages to and from your brain) cannot process pain messages properly. It is also thought that the brain becomes more sensitive to any pain messages that it receives. This may be why fibromyalgia results in constant feelings of pain and extreme sensitivity to pain.

Research has also found that people with fibromyalgia have higher levels of pain transmitting chemicals in their spinal cords compared with those who do not.

Low levels of hormones

People with fibromyalgia have been found to have lower than normal levels of the hormones serotonin, noradrenaline (also known as norepinephrine) and dopamine. Low levels of these hormones may be a key factor in the cause of fibromyalgia.

These hormones each play an important part in controlling many of the processes in the body. For example, serotonin helps to regulate your moods, your appetite, and the way that you sleep. Noradrenaline contributes to attention and your responses, and dopamine helps to control your mood and behavior, and the way that you learn.

Sleep problems

Some researchers think that disturbed sleep patterns may be a cause of fibromyalgia, rather than just a symptom. Fibromyalgia can prevent you from sleeping deeply, which may be due to your brain waking you up slightly every time you begin to enter deep sleep.

External factors and genetic predisposition

In many cases, fibromyalgia develops after an external factor, such as an illness, injury, or operation. It is possible that these external factors may act like a trigger causing fibromyalgia to occur.

There also seems to be a genetic link to fibromyalgia, with some people being more likely than others to develop the condition due to their genes. If this is the case, a genetic predisposition (tendency) could help explain why some people develop fibromyalgia after some sort of trigger.

Other conditions

There are several other conditions that can lead to fibromyalgia. In these cases, the condition is known as secondary fibromyalgia. Some conditions that can cause fibromyalgia are outlined below.

• Joint hypermobility - a condition where your joints are extremely flexible, and can lead to pain, stiffness, and a risk of joint dislocation.
• Lupus - a condition where your immune system attacks your body's connective tissues, such as ligaments and tendons, by mistake.
• Rheumatoid arthritis - joint pain and stiffness which occurs as a result of your immune system attacking the lining of your joints by mistake.

It is also possible that there is no single cause of fibromyalgia, and that several of the above factors may combine to cause the condition.