Recently, I had been to Delhi for a conference at Pragathi Maidhan, where I met a friend from Ram Manohar Lohiya Hospital (RML), New Delhi, who was coughing continuously during our 25-minute discussion. Then I asked him, being an employee of RML, “Why this continuous cough to you? Are you not being to the concerned doctor?” Then he replied that despite taking medicines for the last 3 months, including Homeopathy, Ayurveda, I did not notice much change in the intensity of the cough. Cough is the most important respiratory symptom.
Yes! Cough is an important defence response of the body. It occurs due to irritation of the mucous membrane anywhere in the respiratory tract. Most often, it is indicative of infection of the airways or irritation of the throat, lung tissue, or asthma, a chronic long-term condition that affects the airways in the lungs. The airways are tubes that carry air in and out of the lungs. When there is asthma, the airways can become inflamed and narrowed at times. Cough can also be a symptom of irritation due to tumours, enlarged lymph nodes, inhaled foreign bodies, or toxic fumes of the mucosa.
Sometimes, chronic sinusitis does cause an irritating cough. Then I questioned him. Were you living in Dwarka Sector of Delhi, which seems to be a highly polluted zone, if I remember correctly, that I read about it some time back in the newspaper. He glared at me, yes, I have been residing in Dwarka Sector 8. The cause of his continuous cough is nothing but the pollution levels of the locality of his residence.
According to a survey conducted by the US-based Health Effects Institute in August 2022 of 7,000 world cities, the air pollution in Delhi, the capital territory of India, was found to be the worst of any major city in the world. The air pollution in Delhi also affects the surrounding districts. As per the statement of the World Health Organization, Air pollution in India is estimated to kill about 2 million people every year and is the fifth largest killer in India. India has the world’s highest death rate from chronic respiratory diseases and asthma. In Delhi, poor air quality has irreversibly damaged the lungs of 2.2 million children the future wealth off the country.
It is astonishing that none other than the apex court in the country, the Supreme Court Justice Arun Mishra, remarked that it is “better to get explosives, and kill everyone.” On 25 November 2019, the Supreme Court of India further made a statement on pollution in Delhi, describing “Delhi has become worse than (narak) hell”. During the COVID-19 pandemic lockdown in India, the air quality in Delhi significantly improved, which proves that making Delhi to sleep or locking down the activities of the Delhi population would bring down pollution levels.
Based on the information available and studies conducted, breathing the air in Delhi for two hours, depending on the air quality index (AQI) and the specific amount of PM2.5 pollution, can be roughly equivalent to inhaling the pollutants from one or two cigarettes. PM2.5 stands for particulate matter that has a diameter of 2.5 micrometers or less. It’s also known as fine particulate matter or fine particles. PM2.5 is a type of air pollution that can be harmful to human health. This is not an exact calculation, but it provides a general idea of the health risks involved.
The onset may be acute aspiration of a foreign body, acute episodes of asthma, viral infections, pulmonary oedema, also with diurnal variations; more severe during the night, asthma, left heart failure, pulmonary eosinophilia pneumonia, bronchitis, viral infections, or in the early morning, chronic bronchitis. Cough may be related to occupational exposure to irritants. Byssinosis is a disease of the lungs caused by breathing in inhaling cotton dust or dusts from other vegetable fibers such as flax, hemp, or sisal while at work, or postural bronchiectasis, bronchial asthma. It is a common respiratory symptom of cigarette or beedi smokers. A worsening cough may herald bronchial carcinoma/cancer. In Tuberculosis disease, cough persists for weeks or months with evening rise of temperatures, cough at times with blood, that is haemoptysis, coughing up blood from the lungs or airways. It can range from a small amount of blood-streaked sputum, phlegm, or mucus coughed up to a lot of blood. Massive haemoptysis can be life-threatening, as it can block the airways.
Cough exhibits a long, inspiratory whoop in whooping cough. It loses its explosive character with recurrent laryngeal nerve paralysis. Laryngeal nerve paralysis, also known as vocal cord paralysis, occurs when the nerve impulses to the voice box (larynx) are disrupted, leading to paralysis of the vocal cord muscles. This can affect both vocal cord movement and the ability to protect the airway, and is referred to as bovine cough. Cough may be hacking with a short, dry, often repeated cough upper respiratory tract infection or tracheal lesion. Cough may be dry or productive of sputum.
The normal amount of daily secretion of mucous glands and goblet cells is 100ml. Goblet cells are specialized epithelial cells that produce and secrete mucus, a gel-like substance. They are found in various tissues, including the respiratory tract, gastrointestinal tract, and reproductive tract. The main function of goblet cells is to protect the lining of these tissues by providing lubrication and trapping foreign particles.
The excess secretion in the lungs may be mucoid, mucopurulent or purulent. Mucoid sputum is clear and white in chronic bronchitis. It becomes purulent in the presence of infection when pus is mixed with mucus, giving it a green or yellow colour. Yellow sputum does not always imply infection, as eosinophils also impart such a colour to the sputum. Some more causes of cough and its treatment will be discussed in the coming issue. (To be continued).