Article by Dr Manasa S, B.A.M.S
Exertional dyspnoea is a medical term used to describe ‘difficulty in breathing on exertion or shortness of breathing on exertion’.
In normal circumstances the breathing is relatively slow and happens without much effort. Difficulty in breathing is when an individual feels fastened and shallow breathing.
Many people feel shortness of breath after strenuous activities which may go away after rest, but if shortness is felt suddenly accompanied by other symptoms like sweating, choking sensation and dizziness, the condition needs a detailed evaluation.
Difficulty in breathing can occur because of a wide range of causative factors from allergies to lung diseases to heart attack. During an episode of shortness of breath, a person feels like not getting enough air into the lungs or a need to take the air in, before letting the inhaled air out.
Difficulty in breathing is normal for people who are accustomed to strenuous physical activity and the breathing is restored to normal levels after taking rest for a while. But, the shortness of breath even without the presence being indulged in excessive activity is alarming and needs prompt evaluation and treatment. The dyspnoea is considered as acute if it lasts for a few hours to a few days but it is considered as chronic if it lasts for more than 4 to 8 weeks.
Other names to exertional dyspnoea
– Breathlessness on exertion
– Dyspnoea on exertion
– Short of breath with activity
– Dyspnoea on effort
– Shortness of breath on exertion
– Exertional breathlessness
Causes of Exertional Dyspnoea
Shortness of breath occurs as a result of varied reasons and due to interaction of many physical and psychological factors. It could also be due to environmental factors like poor quality of air or sudden exposure to toxic gasses.
Below mentioned are the medical conditions wherein ‘exertional dyspnoea’ is one of the chief complaints or may cause ‘shortness of breath’ –
Respiratory causes of exertional dyspnoea
Chronic obstructive pulmonary disease (COPD) – Chronic obstructive pulmonary disease is a group of lung disorders which commonly include emphysema and chronic bronchitis. COPD is associated with breathlessness, fatigue, and difficulty in breathing after walking or exercise. Dyspnoea in COPD is because of damage to lungs.
Asthma – Asthma is a disease of the respiratory system which is associated with inflammation and narrowing of airways. Asthma can cause shortness of breath, wheezing, tightness in the chest, chest congestion and coughing.
Pneumonia – Pneumonia is a disorder related to lungs caused by infection which leads to inflammation and buildup of fluid and pus in the lungs. The symptoms of pneumonia include cough, shortness of breath, chest pain, fever, chills, sweating, muscle pain and exhaustion.
Pulmonary embolism – Pulmonary embolism is a condition where there is a blockage in one or more arteries that leads to lungs. This blockage is most often due to clot from elsewhere in the body, such as legs or pelvis, traveling up to the lungs. The other symptoms of pulmonary embolism are chest pain, cough, difficulty in breathing, wheezing, profuse sweating, abnormal heart rate, dizziness, loss of consciousness and bluish tint to the skin.
Pulmonary arterial hypertension – It is a condition where there is high blood pressure that affects the arteries of the lungs. This happens due to the narrowing or hardening of these arteries and may lead to heart failure. Symptoms of pulmonary hypertension are pain in the chest, shortness of breath, difficulty in exercise and extreme fatigue. Many individuals with pulmonary hypertension notice worsening shortness of breath over a period of time. When shortness of breath is associated with chest pain, or loss of consciousness it requires emergency management.
Croup – It is an illness most commonly caused due to viral infection and children between the age of 6 months and 3 years old are most likely to be affected with croup, but older children can also get affected with croup. This usually starts with symptoms similar to a cold which later leads to loud and barking cough and difficulty in breathing can occur because of continuous coughing. Croup usually occurs at night. Most cases of croup resolve within two weeks but some severe cases may require prompt medical attention.
Sarcoidosis – Sarcoidosis is a condition where the immune system overreacts to form lumps or nodules called granulomas. These granulomas can be found anywhere in the body, but most commonly found in lungs or lymph nodes. The respiratory symptoms of sarcoidosis are cough, shortness of breath, chest pain and wheezing.
Tuberculosis – Tuberculosis is a disorder of lungs which can also affect other parts of the body. The main symptoms of tuberculosis when it affects lungs are chronic cough that lasts for at least 3 weeks, chest pain, dyspnoea, and coughing up of blood or mucus from the lungs along with other systemic symptoms like weakness or progressive fatigue, weight loss, loss of appetite, chills / fever, sweating at night and malaise.
Bronchiolitis – It is a viral infection of the bronchioles that most commonly affects babies younger than 6 months old. Illness looks like a common cold in the initial stage but in a few days, it may be associated with rapid breathing with difficulty, coughing and wheezing.
Interstitial fibrosis of lungs (ILD) – Interstitial fibrosis of lungs is used to denote a group of conditions that cause inflammation and scarring in the lungs. ILD tends to damage the tissues between the small air sacs in the lungs and blood vessels around them. Due to these changes, it becomes difficult for the oxygen to move out of lungs and into the body. The most common symptoms of ILD are shortness of breath, dry cough, fatigue and discomfort in chest.
Cardiac reasons for shortness of breath
Coronary artery disease – Coronary Artery Disease (CAD) is a disease concerned with arteries which supply blood to the heart. In this condition there is hardening and narrowing of the coronary arteries which leads to decreased blood supply to the heart which permanently damages the heart muscle. The important signs and symptoms of coronary artery disease are chest pain, shortness of breath, heart attack.
Arrhythmias – Arrhythmias is a condition associated with irregular heartbeats, affecting the rhythm or heart rate causing the heart to either beat too slow or too fast. In these conditions individuals experience shortness of breath or difficulty in breathing.
Congestive heart failure – There is growing evidence which suggests that excessively increased ventilatory demand and abnormal restrictive constraints on tidal volume expansion with limitations of ventilation is responsible for exertional dyspnoea in congestive cardiac failure. As the disease progresses there is reduced ability to function normal day today activities of living.
Congenital heart disease – congenital heart disease which is also called congenital heart defects is an inherited medical condition related to structure and functioning of the heart. These may lead to problems like difficulty in breathing, breathlessness and abnormal heart rhythms.
Systemic reasons for exertional dyspnoea
Anaemia – Individuals suffering from anaemia experience difficulty in breathing because there aren’t enough red blood cells to transport oxygen. Shortness of breath is seen in both forms of anemia, the acute and the chronic one.
Anxiety – Anxiety is a response of the body to fear. This is commonly known as fight-or-flight response. In situations of anxiety, the body prepares and responds to anxiety in many ways. Shortness of breath is one of the responses to anxiety. Along with shortness of breath other respiratory responses are – increased breathing, tightness in the chest, sensation of suffocation and increased heart rate.
Angioedema – Angioedema is a medical condition where there is acute oedema, or swelling of the area underneath the skin or mucosa generally due to severe allergic reaction, but it may also be due to hereditary reasons. The usual sites of angioedema are the face, such as eyelids, mouth, and tongue; the limbs, such as hands or feet; and the genitals. In some cases, angioedema may affect the throat and airways causing swelling. Although the condition is normal in many cases, severe cases which present with symptoms of sudden or rapid increase in breathing, difficulty or choking sensation while breathing, breathing through nose, dizziness or collapse needs proper treatment.
Obesity – Obesity has an impact on many physiological activities in the body. Among many other impacts, dyspnoea on exertion is also an important sign that needs treatment. In case of obesity, the lung volume and chest wall compliance are reduced because of excess accumulation of adipose tissue in the chest and abdomen. As the respiratory muscles have to work against the accumulated fat in the chest wall, the breathing is increased.
Kidney disease – Due to varied pathological processes, kidney diseases have a direct negative impact on lung functioning. The prognosis worsens for those suffering from chronic kidney diseases. A healthy relationship between kidneys and lungs are crucial for maintaining acid-base balance, control of blood pressure, fluid homeostasis. Feeling of shortness in breath or difficulty in breathing is one of the presenting complaints in acute or chronic kidney failure because of fluid retention in the lungs which makes breathing problematic.
Liver disease – When the liver is not functioning properly, blood vessels in the lungs may dilate. When this becomes severe enough, the lungs lose the capability to transport oxygen effectively. This is seen in approximately 5-32 % of patients with liver cirrhosis. The most important complaint in this condition will be severe shortness of breath and low oxygen levels.
Cancer or tumour – It is estimated that more than 50% of people diagnosed with advanced stage of cancer, and between 50 and 75% of people with lung cancer, experience dyspnoea. Dyspnoea becomes more and more common in the final stages of cancer. It is always not possible to identify the reasons for dyspnoea but few reasons such as anatomical problems directly related to the cancer, like obstruction of the airway by tumour or damage to the tissues and fluid around the lungs; pneumonia, a blood clot in the lungs, weakening or paralysis of the respiratory muscles, and side effects of cancer treatments like chemotherapy or radiation therapy, electrolyte imbalances, anxiety can be considered.
Epiglottitis – Acute epiglottitis is a local inflammation of the supraglottic structures and mainly affects the epiglottitis. The most common presenting features of epiglottitis are difficulty in swallowing secretions, dyspnoea, increased oral saliva, sore throat and muffled voice.
Thyrotoxicosis – Thyrotoxicosis is a condition where the body produces an excess amount of thyroid hormone. Experiencing unexplained weight loss, irregular heartbeat, muscle weakness, anxiety and increased sensitivity to heat. Dyspnoea on exertion is a most commonly reported symptom of thyrotoxicosis. It has been understood that increased dyspnoea could be secondary to respiratory muscle weakness.
Metabolic acidosis – In case of metabolic acidosis, the respiratory centre is stimulated, and leads to hyperventilation. This is in order to compensate for the acidosis. Because of all these, patients with acidosis present with varying degrees of dyspnoea.
Sepsis – Sepsis or septic shock is a systemic inflammatory response syndrome secondary to infection. Most of the time, symptoms of sepsis are nonspecific and include shortness of breath, fever, confusion, anxiety, fatigue and malaise.
Other causes of shortness of breath
– Poor quality of air – like inhaling toxic fumes or smog
– Extremities of temperature
– After strenuous exercise
– Being at high altitude
– Allergies to dust, mold, or pollen grains
– Poor physical conditioning
– Later stages of pregnancy
– Blockage in the airways due to stuffy nose or mucus in the throat
Pathophysiology of dyspnoea
Dyspnoea on exertion is the sensation of difficulty in breathing during physical activity, resulting from interactions with receptors in the central nervous system (CNS), peripheral chemoreceptors, and mechanoreceptors in the respiratory tract. The respiratory centre in the brain, consisting of dorsal and ventral medullary groups and pontine grouping, regulates inhalation and exhalation. Mechanoreceptors provide sensory information on lung volume through slow and rapid adapting receptors, which signal the brain to adjust breathing patterns. Peripheral chemoreceptors in the carotid and aortic bodies monitor oxygen levels and respond to hypoxia by stimulating increased ventilation. Central chemoreceptors in the CNS, particularly in the medulla and retrotrapezoid nucleus, sense pH changes, mainly due to carbon dioxide levels. Changes in pH prompt adjustments in ventilation rates to maintain a balance. The respiratory centres in the brainstem generate the baseline respiratory rhythm, which is modified by sensory input from peripheral and central systems. The resulting neural signal is sent to respiratory muscles, including the diaphragm and intercostal muscles, to regulate breathing.
Individuals who are at higher risk of developing shortness of breathing are as below mentioned –
– Asthma or chronic respiratory conditions like COPD or cystic fibrosis
– Low levels of haemoglobin
– Weakness in the muscles which are involved in the breathing activities, such as diaphragm
– Working or staying in a place which acts as trigger points for the exacerbation of asthmatic episodes
– A compromised immune system
– Heightened risk of developing respiratory disease
– Chronic cigarette smokers
The tests which will guide in diagnosing the causes of dyspnoea include –
– Chest X-ray
– CT scan of chest
– Pulmonary function tests
– Blood tests
Treatment for dyspnoea caused due to systemic reasons
– Medicines to lower blood pressure
– Medications and treatment to control vitamin, mineral, and fluid levels
– Antibiotics through intravenous route
Few lifestyle changes for systemic dyspnoea
– Consumption of iron, vitamin B12, folic acid, and vitamin C supplements
– Limiting or completely avoiding alcohol consumption
– Managing diabetes or metabolic syndrome effectively
– Sticking to a balanced diet and regular exercises
Management of dyspnoea due to environmental reasons
– Avoid exposure to tobacco smoke
– Stop smoking
– Avoiding going to places where the levels of pollution, pollen and smoke are more
– Spending as less time as possible in environments having high levels of mold spores
Signs and symptoms of medical emergency
A sudden onset of difficulty in breathing accompanied by the below mentioned signs and symptoms should call for an emergency treatment.
They include –
– Sensation of choking
– Air hunger
– Pain or pressure in the chest
– Choking sensation
– Feeling difficulty in breathing while lying on the back
– Coughing up blood or bubbly, pinkish mucus
Ayurveda Understanding of Exertional Dyspnoea
A condition called Kshudra Shwasa explained in Ayurveda has been compared to Exertional Dyspnoea. Kshudra Shwasa is one among the five kinds of Shwasa – diseases presenting with ‘difficulty in breathing’ as the main symptom. Shwasa is a term which includes diseases pertaining to respiratory system and also cardiovascular system.
Exertional dyspnoea may be an independent condition or is a part of or is a symptom of some other disease. When it is independent it is not severe and is self-limiting. It may be aggressive and a chronic and troublesome condition when it is secondary to some other disease. Here, the primary disease needs to be cured so as to control dyspnoea on exertion from getting chronic.
Diseases like pandu, sthoulya, medoroga and dhatu kshaya too can cause dyspnoea on exertion and so also the conditions wherein pranavaha, rasavaha and manovaha srotas are either contaminated or damaged.
The treatment should be according to cause. Usually Kshudra Shwasa – dyspnoea on exertion, mainly the primary ones are self-limiting. It goes off and the person is relieved by rest.
Related Reading – ‘Exertional Dyspnoea – Ayurveda Understanding’