Summary: Researchers now think chronic fatigue syndrome and fibromyalgia come from certain changes in the brain. The latest studies point to a problem with neurovascular coupling. That means blood flow to some brain areas is not controlled the way it should be. Both conditions are poorly understood and related, and both are on the rise. People with them look fairly healthy, and their routine lab tests show few changes.
Chronic fatigue syndrome (CFS) and fibromyalgia are rising in the US. Yet we have made little progress in understanding them. There are many theories about what causes them, but still no firm proof for any of them.
CFS and fibromyalgia are different conditions, but they share some traits. People with CFS mainly complain of fatigue that no physical illness explains. People with fibromyalgia mainly complain of body aches and have several tender points. Yet they look quite healthy.
These two conditions might differ, but they share many traits. For example, most of the people living with these conditions are relatively healthy. It means that lab tests do not show any severe health issues. Quite often, these conditions occur after recovering from certain ailments like Lyme disease or COVID.
These conditions are not just about fatigue or body aches. They also bring mood swings, depression, anxiety, brain fog, trouble focusing, physical weakness and much more. Over time, both conditions can be disabling.
But there is no reliable test to confirm CFS or fibromyalgia. So they stay diagnoses of exclusion. That means doctors confirm them only after ruling out other health problems.
With no reliable tests, these conditions are hard to study. It is also hard to track how treatment is going. And there are no effective drugs for them. So doctors often treat patients by trial and error. Some patients get help from painkillers, others from antidepressants, and others from supplements.
To find good tests and treatments for these conditions, we need to understand them better. We need to know what is going on underneath that causes these long-lasting, disabling conditions.
In both conditions, most lab tests are fairly normal. So in recent years, researchers have concluded that these conditions have something to do with changes in the brain. Both are now seen as brain disorders that cause fatigue, low energy, mood changes, memory changes and pain.
Both conditions cause many symptoms typical of brain health issues. So doctors have started to look deep inside the brain to understand CFS and fibromyalgia. They use advanced brain scans to see which brain changes go with these conditions.
In recent years, some researchers have proposed that both conditions come from faulty neurovascular coupling. This means blood flow in different brain areas does not change to meet their needs. That causes fatigue, memory problems, poor focus and body aches.
Neurovascular coupling is how the brain adjusts to changes in energy demand. It sends more blood to the brain areas that need it, which delivers more oxygen and sugar (glucose). And the brain is an energy-hungry organ. It uses almost 20% of the body’s oxygen. So any glitch in the system that controls blood supply to the brain can cause problems.
So neurovascular coupling is key to keeping the brain working normally. When it goes wrong, it can change how you sense things, how you move, your memory, your thinking and more. Brain chemicals (neurotransmitters) seem to help control it. So when those chemicals are thrown off, neurovascular coupling suffers. Right now, this is a focus of ongoing research. Many new imaging studies suggest researchers are on the right track.
Frequently asked questions
What causes fibromyalgia and chronic fatigue syndrome?
Researchers now think both conditions come from changes in the brain. The leading idea is a problem with neurovascular coupling: blood flow to different brain regions does not rise and fall with what those regions need. When a working area of the brain is short on blood, the result can be fatigue, memory trouble, poor focus and body aches. Brain imaging studies are now testing this idea.
What is neurovascular coupling?
It is how the brain sends more blood to the areas working hardest, so they get extra oxygen and glucose. The brain is an energy-hungry organ that uses almost 20% of the body’s oxygen. So this delivery system matters. Brain chemicals help control it. When that control goes wrong, it can change how you sense things, how you move, your memory and your thinking.
Is there a test for fibromyalgia or chronic fatigue syndrome?
No. There is no reliable test to confirm either one, and routine lab tests usually look close to normal. Both are diagnoses of exclusion. That means a doctor confirms them only after ruling out other health problems. The lack of a test also makes these conditions hard to study, and makes it hard to tell if a treatment is working.
What are the symptoms of fibromyalgia and chronic fatigue syndrome?
Chronic fatigue syndrome centers on exhaustion that no physical illness explains. Fibromyalgia centers on body aches and several tender points, often in a person who looks healthy. Both go well beyond tiredness and pain. Mood swings, depression, anxiety, brain fog, trouble focusing and physical weakness are common. Over time, both conditions can be disabling.
Can fibromyalgia or chronic fatigue syndrome start after an infection?
Yes, quite often. Both conditions frequently appear after a person recovers from an illness such as Lyme disease or COVID. The person may seem to have gotten better, yet the fatigue, aches and brain fog stay. Because standard lab work then looks close to normal, researchers have turned to brain scans to find what the blood tests miss.
Dr. Gurpreet Singh Padda, MD, MBA, MHP
