What causes fibromyalgia?
The exact cause of fibromyalgia is unknown, but it's thought to be related to abnormal levels of certain chemicals in the brain and changes in the way the central nervous system (the brain, spinal cord and nerves) processes pain messages carried around the body.
It's also suggested that some people are more likely to develop fibromyalgia because of genes inherited from their parents.
In many cases, the condition appears to be triggered by things that are physical or emotional like an injury, an infection or stress.
Source: Fibromyalgia - NHS (www.nhs.uk)
Who's affected
Anyone can develop fibromyalgia, but it's more common in women than men.
The condition typically develops between the ages of 25 and 55, but people of any age can get it, including children and older people.
It's not clear exactly how many people are affected by fibromyalgia, although research has suggested it could be a relatively common condition.
Some estimates suggest nearly 1 in 20 people may be affected by fibromyalgia to some degree.
One of the main reasons it's not clear how many people are affected is because fibromyalgia can be a difficult condition to diagnose.
There's no specific test for the condition, and the symptoms can be similar to a number of other conditions.