Respiratory conditions lead to chronic inflammation and a gradual weakening of the immune system. Here we delve deeper into the causative factors of both conditions and how herbs can help.
Asthma is a chronic inflammation of the bronchial tubes (airways) that causes swelling and narrowing (constriction) of the airways.
Asthma affects approximately 5 million people in the UK. It can arise at any age, but approximately 50% of asthmatics will start to develop symptoms before the age of 10. 1 in every 11 children will develop asthma and it is classed as the most common chronic condition in the UK (asthma.org.uk).
The inner lining of the airways, or ‘bronchial tubes’ is known as the bronchial mucosa. This includes:
Asthma causes a narrowing of the airways, which interferes with the normal movement of air in and out of the lungs. Asthma involves only the bronchial tubes and does not affect the air sacs or the lung tissue. The narrowing that occurs in asthma is caused by three major factors;
Inflammation in the airways
The first and most important factor causing narrowing of the bronchial tubes is inflammation. Inflammation occurs in response to an allergen or irritant and results from the action of chemical mediators such as histamine, leukotrienes, and others. The bronchial tubes become red, irritated, and swollen and the inflamed tissues produce an excessive amount of “sticky” mucus into the tubes. The mucus can clump together, forming “plugs” that can clog smaller airways. Eosinophils and other cells, which accumulate at the site influence tissue damage and are often shed into the airways, thereby contributing to the narrowing.
During an asthma attack, the muscles around the bronchial tubes tighten, in response to chemical mediators such as histamine and leukotrienes. This is referred to as bronchospasm.
In patients with asthma, the chronically inflamed and constricted airways become highly sensitive, or reactive, to triggers such as allergens, irritants, and infections. Exposure to these triggers may result in chronic inflammation and permanent narrowing of the airways.
The combination of these three factors results in difficulty with breathing out. As a result, the air needs to be forcefully exhaled to overcome the narrowing, thereby causing the typical “wheezing” sound. People with asthma also frequently “cough” in an attempt to expel the thick mucus plugs. Reducing the flow of air may result in less oxygen passing into the blood stream and if very severe, carbon dioxide may accumulate in the blood.
Bronchitis is the inflammation of the bronchi, the air passages that extend from the bronchial tubes and directly into the lungs. An acute Upper Respiratory Infection (URI) is the most common cause of acute bronchitis. The pathology of bronchitis causes the mucosa of the affected bronchi to become inflamed, followed by a dry, nonproductive cough. This is then followed by the production of thick and sticky mucous. Shortness of breath can then result and there may be occasional crackling and wheezing after coughing. Most importantly the excessive mucus floods the ‘muco-ciliary escalator’ (see above) and drastically increases congestion and the risks of secondary infections.
The primary causative factor of bronchitis is viral infection. The most common viruses are adenovirus, coronavirus, influenza A and B viruses, parainfluenza virus, respiratory syncytial virus, coxsackievirus, rhinovirus, and the viruses that cause rubella and measles.
Acute bronchitis will normally only last for between 7-14 days. Symptoms peak within three to five days after the first symptoms appear, and then often resolve within 10-14 days. Serious complications usually occur only in patients with constitutional lung weakness and an underlying chronic respiratory disorder.
Chronic bronchitis is a chronic pulmonary obstructive disorder (CPOD) and is characterised by a chronic productive cough. Chronic bronchitis can result from repeated attacks of acute bronchitis, or it may evolve gradually due to heavy smoking or inhalation of air-borne pollutants. It may have a repetitive pattern and gradually worsen with each occurrence. It is a very common disease in the UK with the large majority of cases being associated with smoking. A damp climate, poor housing and environmental pollution are also other important factors.
In chronic bronchitis there is both hyperplasia and hypertrophy of the mucus-secreting cells. This means that there is excess mucus production and a thickening of the bronchial walls. It is directly implicated with the formation of emphysema.
Smoking is the main cause of chronic bronchitis because it inhibits the efficient functioning of the mucociliary escalator.
Other treatments involve anti-allergenic, bronchodilators, corticosteroids, oxygen therapy and removal of the causative factors