Chronic fatigue syndrome leaves many people completely drained of energy and struggling to think clearly, and their symptoms often worsen after mental or physical exertion -- a reaction known as post-exertional malaise. Researchers studying shortness of breath in people with chronic fatigue have now found that these patients are much more likely to experience dysfunctional breathing. This irregular breathing pattern may be linked to dysautonomia, a disorder involving abnormal nerve control of blood vessels and muscles. By focusing treatment on these breathing irregularities, scientists believe it may be possible to ease some of the debilitating symptoms.
"Nearly half of our chronic fatigue subjects had some disorder of breathing -- a totally unappreciated issue, probably involved in making symptoms worse," said Dr. Benjamin Natelson of the Icahn School of Medicine, senior author of the study published in Frontiers in Medicine. "Identifying these abnormalities will lead researchers to new strategies to treat them, with the ultimate goal of reducing symptoms."
Breathe easy
The study included 57 people diagnosed with chronic fatigue syndrome and 25 healthy individuals of similar age and activity level. All participants completed two days of cardiopulmonary exercise tests. During these sessions, the researchers monitored heart rate, blood pressure, oxygen uptake efficiency, blood oxygen saturation, and how much effort participants used to breathe. They also analyzed breathing rate and patterns to detect signs of hyperventilation and dysfunctional breathing.
Dysfunctional breathing is often seen in asthma patients, but it can develop for many different reasons. Typical features include frequent deep sighs, rapid breathing, forceful exhalation from the abdomen, or chest breathing without proper diaphragm use, which prevents the lungs from fully expanding. It can also involve a lack of coordination between chest and abdominal movements, meaning the muscles that support breathing are no longer working smoothly together.
"While we know the symptoms generated by hyperventilation, we remain unsure what symptoms may be worse with dysfunctional breathing," said Dr. Donna Mancini of the Icahn School of Medicine, first author of the study. "But we are sure patients can have dysfunctional breathing without being aware of it. Dysfunctional breathing can occur in a resting state."
Catching your breath
Results showed that people with chronic fatigue syndrome took in roughly the same amount of oxygen as the control group -- their peak VO2 max was similar. However, 71% of the chronic fatigue group showed breathing abnormalities, such as hyperventilation, dysfunctional breathing, or both.
Almost half of the chronic fatigue participants breathed irregularly during the tests, compared to only four people in the control group. About one-third of the fatigue patients hyperventilated, while just one person in the control group did. Nine patients had both hyperventilation and dysfunctional breathing, a combination not seen in any of the controls.
Both of these breathing disorders can produce symptoms similar to those of chronic fatigue, including dizziness, difficulty concentrating, shortness of breath, and exhaustion. When both occur together, they can also cause chest pain, palpitations, fatigue, and (unsurprisingly) anxiety. The researchers believe that these breathing problems may worsen the effects of chronic fatigue or even play a direct role in post-exertional malaise.
"Possibly dysautonomia could trigger more rapid and irregular breathing," said Mancini. "It is well known that chronic fatigue syndrome patients often have dysautonomia in the form of orthostatic intolerance, which means you feel worse when upright and not moving. This raises the heart rate and leads to hyperventilation."
Pulmonary physiotherapy?
These findings suggest that addressing dysfunctional breathing could help relieve some symptoms of chronic fatigue. The researchers plan to continue investigating how dysfunctional breathing and hyperventilation interact. Although more studies are needed before any official treatments are recommended, they already have several promising ideas.
"Breathing exercises via yoga could potentially help, or gentle physical conditioning where breath control is important, as with swimming," suggested Natelson. "Or biofeedback, with assessment of breathing while encouraging gentle continuous breath use. If a patient is hyperventilating, this can be seen by a device that measures exhaled CO2. If this value is low, then the patient can try to reduce the depth of breathing to raise it to more normal values."