What is fibromyalgia?
If you or a loved one has just received a fibromyalgia diagnosis, you probably have a lot of questions. Many people reach this point after years of being dismissed or misdiagnosed. This page is a gentle starting point.
Fibromyalgia is a long-term condition that causes widespread pain, fatigue, and cognitive difficulties. It does not show up on scans or blood tests, which is often why it takes so long to diagnose — but it is a real, well-established medical condition.
It is not a disease of damaged tissue
For years, fibromyalgia was assumed to be a problem with the muscles or joints themselves. The word ‘fibromyalgia’ literally means ‘pain in the fibrous tissues’.
That understanding has changed. Research suggests fibromyalgia is a condition of the central nervous system — specifically, how the brain and spinal cord process pain signals.
Imagine a sound system with the volume turned up too high. The signals coming in may be no greater than normal — a light touch, a bit of pressure, a change in temperature — but the output is amplified to the point of distortion. In fibromyalgia, the nervous system behaves something like this. Ordinary sensations can be registered as painful, and real pain can feel overwhelming.
The defining feature The defining feature of fibromyalgia is widespread pain — pain in multiple areas of the body, lasting three months or more. Fatigue and cognitive difficulties almost always come with it, but pain is what sets fibromyalgia apart from other chronic illnesses.
How does it start?
Fibromyalgia can affect anyone. It is found in every country and every demographic.
That said, some patterns are consistent:
It frequently coexists with other conditions — including ME/CFS, irritable bowel syndrome, migraine, and chronic pelvic pain.
It is more commonly diagnosed in women than in men, by a significant margin. Some researchers argue this reflects a genuine biological difference. Others suggest it partly reflects diagnostic bias, with men underdiagnosed when presenting with similar symptoms.
It is most often diagnosed between the ages of 30 and 50, but it can affect children, teenagers, and older adults.
Is it the same as ME/CFS?
No — but the two overlap significantly, and some people meet the diagnostic criteria for both.
Both conditions involve fatigue, unrefreshing sleep, and cognitive difficulties. The distinguishing feature is what sits at the centre of the illness. In fibromyalgia, that is widespread pain. In ME/CFS, it is post-exertional malaise (PEM) — a significant worsening of symptoms after physical or mental effort, often delayed by hours or days.
People with fibromyalgia also experience flares — periods where symptoms worsen — but these are not the same as the delayed-crash pattern that defines PEM. Treating the two as interchangeable is a common mistake, and it can lead to management strategies that work well for one condition but not the other.
For more on ME/CFS, see our ME/CFS hub.