TL;DR: No one knows the single cause of fibromyalgia, and anyone who tells you they do is guessing. The current understanding is that the nervous system starts processing pain signals too strongly, a change researchers call "central sensitization." It tends to run in families, often shows up after a physical or emotional trigger like an injury, infection, surgery or prolonged stress, and is most common in women between roughly 30 and 50. It is real, it is not your fault, and it is not something you caused by being weak.
When my wife Elena was first told she had fibromyalgia, her first question was the one almost everyone asks: why me, and why now? It is a fair question, and the honest answer is layered. Here is what the research actually says, checked against the CDC, NIH, Mayo Clinic and the American College of Rheumatology.
So what actually causes fibromyalgia?
The leading explanation is that fibromyalgia is a problem with how the brain and spinal cord handle pain. In people with it, the volume knob on pain is turned up. Ordinary signals that most people barely notice get amplified into real, physical aching. Researchers call this central sensitization. It is why a light touch or a snug waistband can genuinely hurt. The pain is not imagined. The processing is just different.
Is fibromyalgia genetic?
It often runs in families, which points to a genetic component. If a parent or sibling has it, your odds are higher. Genes do not seem to cause it by themselves, though. The current thinking is that some people are born more prone to it, and then something in life sets it off.
What triggers it to start?
For many people there is a starting point they can name. Common triggers reported in the research include a physical injury (a car accident is a classic one), an infection or illness, surgery, or a long stretch of severe emotional stress or trauma. Sometimes it builds slowly with no single event. Elena traces hers to a hard year that stacked illness on top of stress, which lines up with what clinicians see often.
At what age does fibromyalgia usually start?
Most people are diagnosed in middle adulthood, often between 30 and 50, though it can begin earlier or later, and children can have it too. The risk does tend to rise with age.
Where in the body does it usually start?
There is no single starting point that fits everyone. Many people first notice it in the neck and shoulders, or across the back, before it spreads to feel like an all-over ache on both sides of the body. For that early neck, shoulder and back tension, some people find gentle warmth and soft pressure from a shiatsu neck and back massager comforting. Because it is widespread by nature, it rarely stays in one spot for long.
Who gets fibromyalgia the most?
Women are diagnosed far more often than men, by a wide margin. People with other conditions like rheumatoid arthritis, lupus, or long-term anxiety or depression also have higher rates. A family history raises the risk too. None of this means you did anything to bring it on.
What this means on a hard day
Understanding the cause does not switch off the pain, but it can lift some of the self-blame, and that matters more than people expect. Fibromyalgia is a real change in how your nervous system works, not a character flaw. On the days the aching wins, what helps is making comfort easy to reach. We gathered the things people return to most into our Flare-Day Comfort Kit, and the wider comfort collection is built on the same idea. Comfort, never a cure.
For more, see our honest guide to fibromyalgia symptoms and whether fibromyalgia can be cured.
Frequently asked questions
What is the main cause of fibromyalgia?
There is no single proven cause. The leading explanation is central sensitization, where the nervous system amplifies pain signals, usually in someone genetically prone to it after a trigger like injury, infection or prolonged stress.
Is fibromyalgia hereditary?
It tends to run in families, so there is likely a genetic component, but genes alone do not appear to cause it.
At what age does fibromyalgia start?
Most often between 30 and 50, though it can begin at any age, including childhood.
Where does fibromyalgia usually start?
Frequently in the neck, shoulders or back before spreading to a widespread, both-sides-of-the-body ache. There is no universal starting point.
Who is most likely to get fibromyalgia?
Women far more than men, people with a family history, and those with conditions like lupus or rheumatoid arthritis.
This article is general information, not medical advice, and is not intended to diagnose, treat, cure, or prevent any condition. Only a qualified clinician can diagnose fibromyalgia. Sources: CDC, NIH/NIAMS, Mayo Clinic, American College of Rheumatology.
Written by the Soft Days team, a small brand built by a family that lives with chronic illness. Last updated June 2026.