Pages Menu
Categories Menu

Major Causes of Breathlessness

Reasons behind breathlessness

Breathlessness is a feeling that is caused as a result of craving for more air, either at rest or after exertion, propelled by a dip in the oxygen supply to the tissues. This results in a negative feedback in the brain of respiratory receptors. Other definitions that could explain breathlessness are dyspnoea or shortness of breath. Labored breathing on account of breathlessness is very common in people who suffer with chronic diseases like cancer, advanced stage of diabetes, HIV-AIDS, heart ailments, cystic fibrosis, bronchitis, COPD and several other conditions. It is frequently experienced immediately after exertion, after taking meals or while sleeping at night. Breathless is present among pregnant women.

man-breathlessness-labored-breathingThere are several major contributing causes of breathlessness. When breathless affects people suffering with chronic diseases, there are three key causes which relate to heavy breathing through the mouth and chest, leading to breathing patterns that are ineffective. Ineffective breathing patterns can be corrected and breathless may disappear once such patterns are attended to.

This table will highlight some of the clinical results to explain ineffective breathing patterns.

Minute Ventilation Rates (chronic diseases)

Condition Minute
Number of
click below for abstracts
Normal breathing 6 l/min Medical textbooks
Healthy Subjects 6-7 l/min >400 Results of 14 studies
COPD 14 (±2) l/min 12 Palange et al, 2001
COPD 12 (±2) l/min 10 Sinderby et al, 2001
COPD 14 l/min 3 Stulbarg et al, 2001
Cancer 12 (±2) l/min 40 Travers et al, 2008
Heart disease 15 (±4) l/min 22 Dimopoulou et al, 2001
Heart disease 16 (±2) l/min 11 Johnson et al, 2000
Heart disease 12 (±3) l/min 132 Fanfulla et al, 1998
Heart disease 15 (±4) l/min 55 Clark et al, 1997
Heart disease 13 (±4) l/min 15 Banning et al, 1995
Heart disease 15 (±4) l/min 88 Clark et al, 1995
Heart disease 14 (±2) l/min 30 Buller et al, 1990
Heart disease 16 (±6) l/min 20 Elborn et al, 1990
Pulm hypertension 12 (±2) l/min 11 D’Alonzo et al, 1987
Asthma 13 (±2) l/min 16 Chalupa et al, 2004
Asthma 15 l/min 8 Johnson et al, 1995
Asthma 14 (±6) l/min 39 Bowler et al, 1998
Asthma 13 (±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 (±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 (±2) l/min 45 Tantucci et al, 2001
Diabetes 12 (±2) l/min 8 Mancini et al, 1999
Diabetes 10-20 l/min 28 Tantucci et al, 1997
Diabetes 13 (±2) l/min 20 Tantucci et al, 1996
Sleep apnea 15 (±3) l/min 20 Radwan et al, 2001
Liver cirrhosis 11-18 l/min 24 Epstein et al, 1998
Hyperthyroidism 15 (±1) l/min 42 Kahaly, 1998


In these cases above, breathlessness is a result of chronic hyperventilation which reveals presence of automatic deep patterns of breathing. It also leads to alveolar hypocapnia and cell hypoxia indicating lack of carbon dioxide in nerve cells. It creates hunger for air among people and stimulates the respiratory center to intensify the breathing patterns further.

man-exercise-induced-asthma Healthy people only require 500 millileters for the breathing tidal volume with about ten to twelve breaths per minute as the respiratory rate. A person weighing seventy kilograms would normally take six large breaths per minute ventilation, while in a state of rest. But, patients who suffer with labored breathing and breathlessness would measure at twelve large breaths per minute ventilation and this more than double the normal ventilation rate required. Some people with chronic ailments may also clock about eighteen large breaths per minute with a higher respiratory frequency. This results in hypoxic or severe tension in respiratory muscles and constriction of the airways.

Why are people breathless after exertion?

Exertion raises the ventilation rates per minute, causing a loss in alveolar carbon dioxide. Hypocapnia results in a reduction in the oxygen delivery to the essential organs in the body and makes the perfusion-ventilation ratio worse in cases where people are suffering with lung problems, constricting the arterial blood vessels. After exertion, breathlessness becomes stronger in cases where people rely heavily on breathing through the mouth, leading to carbon dioxide loss in alveoli of the lungs and during absorption of nitric oxide in the nasal region. Heavy breathing through the chest is another major factor leading to chronic breathlessness, resulting in losses in blood oxygenation and hypoxemia.

old-man-sleep-heavy-breathing-2 Why are people breathless after consuming meals?

The major physiological impact after consumption of meals is increased ventilation as a result of biochemical stress due to food substances which need redistribution and assimilation. An increase in the respiratory volumes results in exertional dyspnoea.

Breathlessness in pregnant women

Over-breathing is a typical reaction to anxiety and stress, physiologically. When people are anxious, the body experiences a reduced supply of oxygen to the cells and a loss of carbon dioxide in lungs. When people sleep at night and assume a horizontal position, alveolar carbon dioxide gets lowered, resulting in tensions in cellular oxygen. Several studies have also proved that in cases of pregnancy in women, end-tidal carbon dioxide also gets lowered.


This YouTube video highlights the major causes and prescribes treatment of breathlessness which could be successful.

It becomes clear then that exertion after physical exercise results in heavy breathing through the mouth and chest. Heavy breathing is also present soon after eating meals or when people are under stress or going through anxious moments. Poor posture and sleeping in a horizontal position at night also leads to heavy and labored breathing.

Successful Treatment

Over one hundred and sixty doctors in Russia clinically tested thousands of cases who were suffering with labored breathing and breathlessness. The result of the tests revealed that all these cases scored less than twenty seconds in holding their breath when put through the body-oxygen test. The doctors also found that by showing them breathing normalization techniques, these cases were able to eliminate breathlessness.

physicians It was discovered that cases who scored more than twenty seconds in holding their breath during the body-oxygen test did not go through the negative symptoms of breathlessness. The result was achieved during the clinical trials after applying several breathing therapies and training devices such as the Frolov breathing therapy device and the Buteyko breathing method.

Share Button