3.4 Diseases Related To Respiratory System

Introduction

The respiratory system is essential for gas exchange, but it is also exposed to many harmful substances from the environment, such as dust, smoke, and pathogens. As a result, it is prone to various diseases. Some of the most common respiratory disorders include bronchitis, emphysema, pneumonia, asthma, and lung cancer. This topic explains the symptoms, causes, and treatment of these diseases.

Definition

Respiratory diseases are disorders that affect the respiratory system, including the air passageway and lungs. They can impair breathing and gas exchange, leading to serious health problems.

The common respiratory disorders are:

• Bronchitis
• Emphysema
• Pneumonia
• Asthma
• Lung cancer

Main Idea

The common respiratory disorders are Bronchitis, Emphysema, Pneumonia, Asthma, and Lung cancer. Each disease has specific symptoms, causes, and treatments.

Core Concept

Overview of Respiratory Diseases

Detailed Explanation

1. Bronchitis

What it is: Bronchitis is the inflammation of the lining of the air passages like trachea, bronchi, and bronchioles.

Symptoms:

• Secretion of excess mucus from the goblet cells in response to irritation.
• Cough, which occurs repeatedly.
• Coughing and breathlessness increase as the disease progresses.
• Bronchitis can be acute or chronic.

Causes:

• Acute bronchitis: Usually lasts a few days only and is a side effect of viral infections like flu.
• Chronic bronchitis: Most commonly caused by smoking and to a lesser extent by air pollution. It may last for months.

What happens:

- The sensation of breathlessness occurs due to reduced gas exchange.

Types:

Treatment:

• The infection will generally go away on its own within one week.
• Steps for some relief:
• Do not smoke.
• Drink plenty of fluids.
• Take rest.
• An inhaler may be taken.
• If your doctor thinks that you have a secondary bacterial infection, antibiotics may be prescribed.

Simple explanation: Bronchitis is when the airways become inflamed and produce too much mucus, causing a persistent cough.

2. Emphysema

What it is: Emphysema is a respiratory disease where there is over-inflammation of the alveoli in the lungs, causing a decrease in lung function.

Symptoms:

• The main sign of emphysema is increasing breathlessness.
• In advanced cases, the patient finds it difficult to walk.
• The lungs lose elasticity, so it becomes more difficult to exhale air.
• Inflammation and narrowing of the finer bronchioles also occur.

Causes:

• It is due to gradual breakdown of the thin walls of alveoli and the total surface area for gaseous exchange decreases.
• The main cause is long-term irritation of the lungs, most commonly by cigarette smoke, air pollution, or industrial dust.

What happens:

• The walls of the alveoli break down.
• The total surface area for gas exchange decreases.
• The lungs lose elasticity.
• It becomes difficult to exhale air.

Treatment:

• Treatment methods for emphysema do not cure or reverse the damage to the lungs.
• The best way to prevent emphysema is to avoid smoking.
• A variety of medications may be used in the treatment of emphysema.

Simple explanation: Emphysema is when the tiny air sacs in the lungs are damaged and lose their elasticity. This makes it hard to breathe out.

3. Pneumonia

What it is: Pneumonia is defined as an inflammation of the alveoli of lungs caused by acute infection.

Double pneumonia: A lung infection that affects both lungs.

Symptoms:

• Fever
• Shaking chills
• Chest pain
• Cough
• Headache
• Sore throat
• Nausea
• Diarrhoea

Causes:

- The most common cause of pneumonia is bacteria Streptococcus pneumoniae.

Treatment:

- Antibiotics are prescribed for bacterial pneumonia.

Simple explanation: Pneumonia is an infection that causes the alveoli to become inflamed and fill with fluid, making it hard to breathe.

4. Asthma

What it is: Asthma is the common chronic inflammatory disease of the airways.

Symptoms:

• The person has more difficulty in breathing out than breathing in.
• A characteristic whistling sound is caused by breathing.
• There is secretion of excess mucus and swelling of the lining of the respiratory pathway.

Causes:

• It is due to an allergic response to substances like:
• Pollen
• Household dust
• A particular food
• Feathers from pillow
• Cold air
• Exercise
• Smoking
• Emotional disturbance may also provoke an attack.

Treatment:

• Mild attack of asthma is controlled with bronchodilators that dilate the airway.
• Different devices called inhalers help asthma patients to breathe.
• Asthma is a long-term disease that has no cure.
• Asthma is treated with two types of medicines:
• Long-term control
• Quick-relief medicines

Simple explanation: Asthma is when the airways become narrow and inflamed due to an allergic reaction, making it hard to breathe.

5. Lung Cancer

What it is: Cancer is caused by cells dividing repeatedly out of control and forming unspecialised masses of cells called tumours. Lung cancer usually starts in the epithelium of the bronchioles. It then usually spreads throughout the lungs.

Symptoms:

• The first event appears to be thickening and callusing of the cells lining the bronchi.
• Then there is a loss of cilia, so that it is impossible to prevent dust and dirt from settling in the lungs.
• After that, a tumour consisting of cancerous cells with an atypical nucleus appears at one location.
• Due to metastasis, the cancer spreads.
• The tumour may grow until the bronchus is blocked, cutting off the supply of air to that lung.

Causes:

• Tobacco smoke is the main cause of cancer.
• Air pollution also increases the risk of lung cancer, especially car exhaust, asbestos, and arsenic.

Treatment:

- The only treatment is pneumonectomy, i.e., to remove a lobe or the lung completely, or destroying it through radiation.

Simple explanation: Lung cancer is when cells in the lungs grow out of control and form a tumour. Smoking is the main cause.

Intermediate Level

Key points:

• Smoking is a major cause of bronchitis, emphysema, and lung cancer.
• Asthma is an allergic response.
• Pneumonia is caused by bacteria.
• Emphysema and lung cancer cause permanent damage.

Important Points

• - Bronchitis is the inflammation of the lining of the air passages.
• - Symptoms of bronchitis include excess mucus, cough, and breathlessness.
• - Acute bronchitis is usually caused by viral infections.
• - Chronic bronchitis is most commonly caused by smoking.
• - Emphysema is a respiratory disease where there is over-inflammation of the alveoli.
• - The main sign of emphysema is increasing breathlessness.
• - Emphysema is caused by gradual breakdown of the thin walls of alveoli.
• - Pneumonia is an inflammation of alveoli of lungs caused by acute infection.
• - The most common cause of pneumonia is bacteria Streptococcus pneumoniae.
• - Asthma is a common chronic inflammatory disease of the airways.
• - Asthma is due to an allergic response.
• - Asthma is treated with bronchodilators and inhalers.
• - Lung cancer usually starts in the epithelium of the bronchioles.
• - Tobacco smoke is the main cause of lung cancer.
• - Treatment of lung cancer is pneumonectomy or radiation.

Remember

• - Bronchitis = inflammation of airways
• - Emphysema = breakdown of alveoli walls
• - Pneumonia = infection of alveoli
• - Asthma = allergic narrowing of airways
• - Lung cancer = uncontrolled cell growth
• - Smoking = major cause of bronchitis, emphysema, lung cancer
• - Asthma = treated with bronchodilators and inhalers
• - Pneumonia = treated with antibiotics
• - Emphysema = no cure, prevention is best
• - Lung cancer = treated with surgery or radiation

Common Mistakes

• 1. Confusing bronchitis and asthma.
• - Bronchitis = inflammation of airways due to infection or smoking.
• - Asthma = allergic narrowing of airways.
• 2. Thinking emphysema is curable.
• - Emphysema causes permanent damage. Treatment only relieves symptoms.
• 3. Believing pneumonia is always caused by bacteria.
• - Pneumonia can also be caused by viruses and fungi.
• 4. Mixing up the symptoms of bronchitis and pneumonia.
• - Bronchitis = cough, excess mucus.
• - Pneumonia = fever, chills, chest pain.
• 5. Thinking lung cancer only affects smokers.
• - Non-smokers can also get lung cancer, though smoking is the main cause.
• 6. Forgetting that asthma has no cure.
• - Asthma is a long-term disease. Treatment controls symptoms but does not cure it.
• 7. Believing emphysema only affects older people.
• - Emphysema can affect younger people, especially smokers.

Quick Revision

60-Second Revision

• Bronchitis = inflammation of airways; cough, mucus; smoking/viral infection
• Emphysema = breakdown of alveoli; breathlessness; smoking; no cure
• Pneumonia = infection of alveoli; fever, chills; bacteria; antibiotics
• Asthma = allergic narrowing of airways; wheezing; bronchodilators
• Lung cancer = uncontrolled cell growth; tumour; smoking; surgery/radiation
• Smoking = major cause of bronchitis, emphysema, lung cancer
• Warning: Do not confuse bronchitis (inflammation of airways) with pneumonia (infection of alveoli).