Breathlessness Causes, Reasons, and Solutions
Breathlessness is a sensation of air hunger and an uncomfortable awareness of one's own breathing at rest or on exertion due to low oxygenation of tissues and the negative feedback of the respiratory receptors in the human brain. Other similar terms are "dyspnea" and "shortness of breath". Breathlessness and labored breathing are common in people with chronic diseases, such as advanced diabetes, cancer, cystic fibrosis, HIV-AIDS, heart disease, COPD, bronchitis, and many other conditions. It can appear on exertion, after meals, during night sleep, or at pregnancy.
Causes of breathlessness
There are many contributing reasons that can lead to breathlessness. However, in cases of chronic diseases, there are 3 main causes of breathlessness that relate to mouth breathing, chest breathing and ineffective breathing patterns. This last cause plays the central role since its elimination leads to disappearance of breathlessness. Consider these clinical results.
Minute ventilation rates (chronic diseases)
click below for abstracts
|Normal breathing||6 l/min||-||Medical textbooks|
|Healthy Subjects||6-7 l/min||>400||Results of 14 studies|
|COPD||14 (~+mn~2) l/min||12||Palange et al, 2001|
|COPD||12 (~+mn~2) l/min||10||Sinderby et al, 2001|
|COPD||14 l/min||3||Stulbarg et al, 2001|
|Cancer||12 (~+mn~2) l/min||40||Travers et al, 2008|
|Heart disease||15 (~+mn~4) l/min||22||Dimopoulou et al, 2001|
|Heart disease||16 (~+mn~2) l/min||11||Johnson et al, 2000|
|Heart disease||12 (~+mn~3) l/min||132||Fanfulla et al, 1998|
|Heart disease||15 (~+mn~4) l/min||55||Clark et al, 1997|
|Heart disease||13 (~+mn~4) l/min||15||Banning et al, 1995|
|Heart disease||15 (~+mn~4) l/min||88||Clark et al, 1995|
|Heart disease||14 (~+mn~2) l/min||30||Buller et al, 1990|
|Heart disease||16 (~+mn~6) l/min||20||Elborn et al, 1990|
|Pulm hypertension||12 (~+mn~2) l/min||11||D'Alonzo et al, 1987|
|Asthma||13 (~+mn~2) l/min||16||Chalupa et al, 2004|
|Asthma||15 l/min||8||Johnson et al, 1995|
|Asthma||14 (~+mn~6) l/min||39||Bowler et al, 1998|
|Asthma||13 (~+mn~4) l/min||17||Kassabian et al, 1982|
|Asthma||12 l/min||101||McFadden, Lyons, 1968|
|Cystic fibrosis||15 L/min||15||Fauroux et al, 2006|
|Cystic fibrosis||10 L/min||11||Browning et al, 1990|
|Cystic fibrosis*||10 L/min||10||Ward et al, 1999|
|CF and diabetes*||10 L/min||7||Ward et al, 1999|
|Cystic fibrosis||16 L/min||7||Dodd et al, 2006|
|Cystic fibrosis||18 L/min||9||McKone et al, 2005|
|Cystic fibrosis*||13 (~+mn~2) l/min||10||Bell et al, 1996|
|Cystic fibrosis||11-14 l/min||6||Tepper et al, 1983|
|Diabetes||12-17 l/min||26||Bottini et al, 2003|
|Diabetes||15 (~+mn~2) l/min||45||Tantucci et al, 2001|
|Diabetes||12 (~+mn~2) l/min||8||Mancini et al, 1999|
|Diabetes||10-20 l/min||28||Tantucci et al, 1997|
|Diabetes||13 (~+mn~2) l/min||20||Tantucci et al, 1996|
|Sleep apnea||15 (~+mn~3) l/min||20||Radwan et al, 2001|
|Liver cirrhosis||11-18 l/min||24||Epstein et al, 1998|
|Hyperthyroidism||15 (~+mn~1) l/min||42||Kahaly, 1998|
In all these cases, breathlessness is caused by chronic hyperventilation (or an automatic deep breathing pattern) leading to alveolar hypocapnia (lack of CO2) and cell hypoxia, which creates air hunger and provokes the respiratory center to further intensify breathing.
Breathing of healthy people is small: only 500 ml for tidal volume, 10-12 breaths/min for the respiratory rate, and 6 L/min for minute ventilation for a 70-kg person). But patients with breathlessness and labored breathing have over 12 L/min (more than double the norm) for their ventilation rates and over 18 breaths/min for respiratory frequency. That causes constriction of airways and hypoxic and tense respiratory muscles.
What causes breathlessness on exertion?
Exertion increases minute ventilation rates and this causes losses in alveolar CO2. Hypocapnia either worsens ventilation-perfusion ratio (in case of lung problems) or immediately constricts arterial blood vessels, causing reduced oxygen delivery to all vital organs. In both cases, increased breathing reduces oxygen transport to tissues. Breathlessness on exertion is particularly strong in cases of mouth breathing that leads to more losses in CO2 and additional losses in absorption of nasal nitric oxide.
Chest breathing is another crucial factor that leads to chronic breathlessness due to drastic reduction in blood oxygenation, sometimes leading to hypoxemia.
What causes breathlessness after eating
The main physiological effect of meals and eating is also increased ventilation due to biochemical stress caused by food substances that require assimilation and redistribution. Increased respiratory volumes cause the same effects as it is described above for exertional dyspnea.
Why anxiety, night sleep, and pregnancy trigger breathlessness
Overbreathing is a normal physiological reaction to stress. As a result of stress and anxiety, the human body has reduced oxygenation of cells and diminished carbon dioxide in the lungs. Transition into a horizontal position also results in lowered alveolar CO2, leading to decreased cellular oxygen tensions. Numerous studies proved that end-tidal CO2 is lowered in pregnancy, causing the same effects as described above.
As a result, in all these cases, the main physiological mechanism remains the same: all these factors increase minute ventilation rates, causing reduced oxygen levels in body cells.
The main causes of
breathlessness and labored
breathing (why it is hard to breathe):
- constriction of airways due to hypocapnia in the airways
- reduced oxygen levels in the diaphragm and chest muscles due to reduced oxygen transport
- tense states in the diaphragmatic and chest muscles due to arterial hypocapnia.
Exacerbating reasons in the pathophysiology of labored breathing and
- mouth breathing (due to reduction in nitric oxide absorption and alveolar CO2)
- chest breathing (due to reduction in arterial oxygenation)
- presence of inflammation and mucus in airways, causing further narrowing or an obstruction of air flow (as in COPD).
This YouTube video explains the main causes and successful treatment of breathlessness or shortness of breath.
Exertion, mouth breathing, physical exercise with mouth breathing, chest breathing, meals (eating and especially overeating), overheating, anxiety, stress, attempts to inhale deeply, deep breathing exercises with CO2 losses, poor posture, night sleep and many other factors are known causes of hyperventilation. Hence, they worsen breathlessness and labored breathing.
Successful treatment of breathlessness
Over 160 Russian medical doctors tested thousands of people with breathlessness and labored breathing and found that all of them had less than 20 seconds for the body-oxygen test. These doctors also discovered that breathing normalization (achieving normal breathing parameters) leads to complete elimination of breathlessness and labored breathing with air hunger.
As their clinical experience revealed, with over 20 s for the body-oxygen test, patients do not experience these negative symptoms. This result has been achieved in many clinical trials after the application of various breathing therapies and devices (the Buteyko method, Frolov breathing device therapy, and others).
Reference pages: Breathing norms and the DIY body oxygen test:
- Breathing norms: Parameters, graph, and description of the normal breathing pattern
- Body-oxygen test (CP test) : How to measure your own breathing and body oxygenation (two in one) using a simple DIY test
References: pages about CO2 effect:
- Vasodilation: CO2 expands arteries and arterioles facilitating perfusion (or blood supply) to all vital organs
- The Bohr effect: How and why oxygen is released by red blood cells in body tissues
- Nerve stabilization: Carbon dioxide has powerful calmative and sedative effects on brain neurons and nerve cells
References (shortness of breath or breathlessness)
Thorax. 2011 Mar;66(3):240-6.
Neural respiratory drive, pulmonary mechanics and breathlessness in patients with cystic fibrosis.
Reilly CC, Ward K, Jolley CJ, Lunt AC, Steier J, Elston C, Polkey MI, Rafferty GF, Moxham J.
Rev Esp Cardiol. 2005 Oct;58(10):1142-4.
[The circulating NTproBNP level, a new biomarker for the diagnosis of heart failure in patients with acute shortness of breath].
[Article in Spanish]
Aust Fam Physician. 2005 Jul;34(7):541-5.
Shortness of breath - is it chronic obstructive pulmonary disease?
Institute for Breathing and Sleep, Austin Hospital, Heidelberg, Victoria, Australia.
Int J Cardiol. 2002 Sep;85(1):133-9.
Origin of symptoms in patients with cachexia with special reference to weakness and shortness of breath.
Medsurg Nurs. 2000 Aug;9(4):178-82.
Helping patients with COPD manage episodes of acute shortness of breath.
Division of Pulmonary and Critical Care Medicine, Henry Ford Hospital, Detroit, MI, USA.
The most disabling and frightening symptom experienced by patients with COPD is dyspnea. Even with the use of bronchodilators, the symptom may not be completely relieved. Patients often develop their own strategies for managing shortness of breath, including the use of a breathing technique called pursed-lip breathing. Although most nurses are familiar with this breathing technique, they often have difficulty assisting patients to use it during acute episodes of shortness of breath. A strategy is described which nurses can use to assist patients in implementing pursed-lip breathing effectively during episodes of acute dyspnea.
Or go to Causes of Hyperventilation
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