The confusing causes of shortness of breath

You can easily identify several diseases that can cause shortness of breath (called in the professional language Dyspnea), including asthma, lung infection and chronic obstructive pulmonary disease (COPD, a general term for several medical conditions that irreversibly impair the flow of air through the lungs). Heart failure, a condition in which the heart does not pump blood properly and therefore cannot deliver enough oxygen and nutrients to the body, also impairs breathing. But apart from these medical conditions, patients with shortness of breath are often also "unlucky" because they do not receive an accurate diagnosis or effective treatment.

And indeed, it seems that the seemingly basic act of breathing is more complex than scientists thought. New studies are trying to understand how it works and why it goes wrong. The science of understanding why breathing is impaired is still in its infancy, but new insights are already encouraging researchers to develop new tools to target the underlying causes of some mysterious cases and devise ways for doctors to help patients breathe more easily.

diagnostic difficulties

To get an idea of ​​the degree of complexity in identifying the causes of shortness of breath, let us consider an imaginary scenario presented by C. Todd Olin, a pulmonary physician at the Jewish Health Center in Denver, Colorado. A shy 16-year-old girl who is under a lot of stress and tension claims that "it's just hard for her to breathe properly." By the time she gets to the lung disease specialist she has probably already seen four or five doctors to no avail.

The specialist refers her to a series of routine tests to detect the most expected diseases, starting withasthma, a disease that is sometimes accompanied by inflammation that can cause temporary swelling in the respiratory tract, narrowing of the passages and accumulation of mucus. As a result, patients suffer from shortness of breath and wheezing, and their breaths make whistling noises in the chest. Exercise can trigger asthma symptoms, but this patient is inactive and unresponsive to asthma medications. in inspection Spirometry, which measures air flow during breathing, no results corresponding to asthma or COPD are obtained. Moreover, when the experts listen to the lungs and heart for signs of decreased function, and look at the movements of the chest, throat and other relevant body parts, the inhalations and exhalations are more like frequent, deep sighs than the wheezing characteristic of asthmatics.

The doctor refers to a chest x-ray, an EKG and a CT scan to check if the patient suffers from an infection, or if a foreign body is in her trachea or esophagus, or if there are signs of cancer or heart disease. But the results of all the tests are normal, including an examination of the vocal cords, the purpose of which is to examine a narrowing of the vocal cords that blocks the passage of air.

If so, the doctor checks the patient's breathing more meticulously. The patient wears a plastic mask connected to a device that collects samples of the exhaled air. The samples are channeled to sensors that measure air flow, oxygen and carbon dioxide levels in real time, and more. The data show an irregularity in the amount of air inhaled by the patient: she alternately inhales 20 liters in one minute and eight liters in a second. A blood test shows normal levels of dissolved oxygen and slightly low levels of carbon dioxide, indicating that the patient is consuming sufficient amounts of oxygen but exhaling too much.

On the path of denial, the doctor eventually diagnoses the young woman with "Dysfunctional breathing", a mysterious disease that researchers have only recently begun to recognize. Dysfunctional breathing, also known as dysfunctional dyspnea, may accompany and worsen symptoms of asthma, COPD, and other conditions, but it can also stand on its own. As Olin's scenario suggests, there is no medical consensus on the most successful criteria for diagnosing dysfunctional breathing. To add and complicate, says Mark L. Everard From the University of Western Australia, patients do not always seek medical help because they have adapted behavior that prevents symptoms, such as stopping singing or engaging in competitive sports. Because of this, people suffering from the disease, which some estimate affects 10% of adults at some point in their lives, are often not diagnosed or they are diagnosed with another disease and then they receive inappropriate treatment.

It is not clear what exactly causes dysfunctional shortness of breath, but many experts suspect that the condition stems from a biomechanical or psychological disorder or a combination of the two. One possible cause is breathing that originates only from the upper chest instead of the entire chest and abdomen.

There is still no accepted treatment for dysfunctional breathing. By the time patients are diagnosed, it is assumed that they have already tried, without success, bronchodilator-type medications beta agonists, which cause the airways to relax to make breathing easier. However, other combinations of beta agonists may also help. Some of those suffering from this condition may receive instruction on how to breathe properly while resting and moving, as well as psychological counseling, if the doctors believe that there is an involvement of emotions or a feeling of pressure and mental stress. Over time, patients often learn to better control their breathing, and the condition resolves. And yet, the treatment may have resolved the symptoms but did nothing to treat the root of the problem.

purify the air

Experts agree that better treatment of patients with shortness of breath will involve a sharper understanding of the processes surrounding inhalation and exhalation and the mechanisms underlying breathing problems. Improved technology for measuring breathing patterns and clearer criteria for diagnosing dysfunctional breathing are also important.

Of course, scientists know quite a bit about the body's control mechanisms for breathing. They understand that the signals sent from the brainstem instruct the muscles of the throat, chest and abdomen, and especially the diaphragm, to expand and contract involuntarily, and draw in and expel air. And obviously we also have a certain ability to control our breathing, we can slow it down or speed it up at will, and breathe deeper or shallowly. Similarly, we can coordinate it with swallowing, speaking, singing and eating. But if you dig deeper into the science of dysfunctional breathing, the picture becomes much murkier.

Admittedly, lung and respiratory researchers face special challenges. The lungs play at least three roles: they bring in oxygen and remove carbon dioxide, they regulate the balance of acids and bases in the body, a balance necessary for the proper functioning of the organs, and they filter out the abundance of foreign particles that we constantly inhale. In some ways the lung is therefore more complex than the kidneys or the heart, he says Richard Castriota From the University of Texas Health Center at Houston.

Moreover, the breathing process involves many body systems, starting with the central and peripheral nervous system and ending with the respiratory and digestive systems. "If you go to the doctor and say, 'It's hard for me to breathe,' there are so many different diseases and conditions, poor postures and breathing methods that could underlie the problem," she says Gina and S from Duke University. "You may contact a cardiologist, a pulmonologist, an otolaryngologist, a physical therapist, a respiratory therapist, or a psychiatrist."

Still, the emerging field of respiratory research (which is distinct from the more general field of Pulmonology) provides new insights into various respiratory disorders. For example, Olin figured out how to test the voice boxes in real time, or thelarynx, of athletes suffering from shortness of breath caused by physical activity, a different phenomenon from dysfunctional breathing. It equips the treated athletes with a helmet to which it is attached Endoscope which shows the larynx while the athletes pedal an exercise bike. He and his research group found that when these athletes exercised at maximum intensity, their voice boxes narrowed more severely than when they were engaged in moderate activity or at rest. These observations imply that perhaps the structure of the upper part of the airways of athletes is different from its structure in the general population or that they react differently behaviorally to strenuous activity. Surveys of the scientific literature regarding dysfunctional breathing also provide insight. Stephen J. Fowler from the University of Manchester in England and his colleagues recently reviewed dozens of articles on the disease to determine the ways in which it is manifested, diagnosed and treated. Their analysis revealed five common types of dysfunctional breathing and the breathing patterns that characterize them. The findings could ultimately help doctors adapt the treatment in the best way to the patient's needs.

However, it may be some time before these discoveries yield clinical applications. In the near future, people suffering from breathing problems can hope that doctors will reach a better agreement about the standard methods of diagnosis and treatment. To this end, Fowler and others, who treat and study dysfunctional breathing, have been meeting in London every week for the past six months to discuss difficult cases.

Lung experts agree on the state to strive for: natural breathing. Vess says that people can often help themselves reach this goal. For example, they can avoid tight clothing that restricts chest and abdominal movement and relax bowel movements to supplement and help release respiratory muscles. In extreme cases, excess belly fat can also interfere with inhalation and exhalation, says Castriota, so maintaining a healthy weight is also important.

So when should you worry about shortness of breath? Castriota recommends that people who find that during exercise, such as walking or climbing stairs, they struggle to keep up with others their age, must be tested.

People without shortness of breath may wonder if they, too, should take steps to tune up their breathing system. The answer, says Michael Kohl from the University of British Columbia, she didn't. Deep breathing exercises, such as yoga breathing, can help reduce stress and anxiety. But even during practice, our innate respiratory control system often does a good job of supplying oxygen and removing carbon dioxide produced in the metabolic process. "In the narrowest sense of the word 'health', meaning the absence of disease, there is no need to perform special breathing exercises," Kohl says. In other words: you can already exhale.