Respiratory Diseases

What are Respiratory Diseases?

Respiratory diseases are conditions that affect the respiratory system. These diseases range from mild infections, such as the common cold, to chronic conditions like asthma, and serious illnesses such as lung cancer.

Respiratory diseases affect the organs and structures involved in breathing:

• Nose and nasal cavity
• Pharynx
• Larynx
• The Bronchi, bronchioles, and alveoli
• Lungs
• Muscles that assist in breathing (diaphram & rib cage muscle)

Transmission of Respiratory Diseases

Transmission of infection through droplets or through the air:

• Tiny droplets containing viruses or bacteria are released when an infected person coughs, sneezes, talks or breathes.

Contact Transmission

• Direct contact: Contact with skin, saliva, or other body fluids — e.g., hugging, kissing, or shaking hands.
• Indirect contact: Touching contaminated surfaces (like doorknobs or tables) and then touching your mouth, nose, or eyes can spread infections.

Classification of Respiratory Diseases

Respiratory diseases can affect various parts of the lungs and airways. They are classified based on several factors, such as the cause (viral, bacterial, allergic), the location (upper or lower respiratory tract), and the nature (acute or chronic). This classification helps doctors diagnose and treat effectively.

Infectious Respiratory Diseases

Upper Respiratory Tract Infections (URTIs): It affects the nose, sinuses, throat, and larynx.

• Common cold: Usually caused by viruses; symptoms include sneezing, nasal congestion, sore throat.
• Sinusitis: Inflammation of the sinuses, can be viral or bacterial.
• Pharyngitis/Tonsillitis: Pharyngitis affects the pharynx, tonsillitis affects the tonsils; often viral (e.g., adenovirus) but may be bacterial (e.g., Group A streptococcus).
• Laryngitis: Inflammation of the larynx (hoarse voice, dry cough)

Lower Respiratory Tract Infections (LRTIs): It affects the trachea, bronchi, and lungs.

• Acute bronchitis: Inflammation of bronchi, usually viral; cough is the main symptom.
• Pneumonia: Infection of lung tissue; can be bacterial, viral, or fungal.
• Pulmonary Tuberculosis: Caused by Mycobacterium tuberculosis; symptoms include chronic cough, weight loss, and night sweats.
• Influenza: It is a viral infection that affects the lungs and bronchial tubes. Its caused by influenza viruses, and its symptoms a

Chronic Respiratory Diseases

• Asthma: Chronic airway inflammation causing reversible airway obstruction; triggered by allergens, exercise, or infection.
• Chronic Obstructive Pulmonary Disease (COPD): Includes chronic bronchitis (productive cough >3 months) and emphysema (alveolar destruction).
• Bronchiectasis: Permanent bronchi dilation, excess mucus buildup due to repeated infections or cystic fibrosis.
• Pulmonary Fibrosis: Progressive lung tissue scarring leading to stiffness and impaired oxygen exchange.

Occupational/Environmental Respiratory Diseases

• Pneumoconiosis: Caused by inhaling dusts like silica (silicosis) or asbestos (asbestosis).
• Hypersensitivity pneumonitis: Lung inflammation caused by inhaled organic antigens (e.g., mold, bird feathers)

Neoplastic Diseases

• Lung Cancer: Mainly caused by smoking; includes non-small cell types (adenocarcinoma, squamous cell carcinoma) and small cell carcinoma.
• Mesothelioma: Rare cancer affecting lung lining; strongly associated with asbestos exposure.

Vascular Diseases

• Pulmonary Embolism: Blood clot blocking a pulmonary artery; causes sudden chest pain and shortness of breath.
• Pulmonary Hypertension: High blood pressure in pulmonary arteries; can lead to heart failure.

Sleep-related Breathing Disorders

• Obstructive Sleep Apnea (OSA): Repeated airway collapse during sleep, causing snoring and daytime fatigue.

Genetic Diseases

• Cystic Fibrosis: A genetic disorder leading to buildup of sticky, thick mucus that can damage lungs and other organs.

Risk Factors and Causes of Respiratory Diseases

• Infections: Bacteria, viruses, fungi
• Smoking: Leading cause of COPD and lung cancer
• Air Pollution: Indoor and outdoor
• Allergens: e.g., dust
• Genetics: e.g., cystic fibrosis
• Autoimmune diseases: e.g., sarcoidosis, vasculitis
• Occupational exposure: chemicals, dust, asbestos
• Other factors: Obesity

Signs and Symptoms

• Sputum
• Fever
• Tiredness and fatigue
• Cough and sore throat
• Night sweats and sore throat
• Chest pain
• Wheezing and hoarseness
• Shortness of breath
• Hemoptysis (coughing up blood)
• Frequent sneezing
• Nasal congestion
• Loss of appetite and weight

Diagnosis

• History & Physical Exam: Doctor asks about symptoms, smoking, dust/chemical/infection exposure.
• Blood Tests (CBC, CRP, ESR): These tests check for signs of infection (high white bloodcell count) and inflammation in the body.
• Pulse Oximetry: A small device on your finger measures how much oxygen is in your blood, helping assess how well you ‘rebreathing.
• Chest X-ray: A quick, painless test that shows lung infections (likepneumonia), tumors, or fluid around the lungs.
• CT or MRI Scans: A more detailed scan that helps identify tumors,scarring, or hidden infections in the lungs.
• Pulmonary Function Test: A breathing test that measures how well air moves in and out of your lungs; it’s useful for asthma and COPD.
• Sputum Analysis: A sample of mucus from your cough is tested to see if bacteria or TB germs are present.
• Bronchoscopy: Thin tube with camera to inspect airways and collect samples.
• Mantoux test (PPD): Skin test for tuberculosis exposure.
• Biopsies: These are medical procedures where a small tissue sample is taken from a specific part of the body (such as the lung or lymph nodes) to be examined in the laboratory

Treatment & Management

Prevention

• Vaccinations: Influenza, COVID-19, RSV, pneumococcal, respiratory syncytial virus (RSV)
• Quitting/abstaining from smoking: Reduces risk of COPD and lung cancer
• Improve air quality: Reduce indoor and outdoor pollutants
• Protective equipment: Especially for occupational exposures
• Hand hygiene and mask use: To reduce respiratory infection spread
• Healthy lifestyle: Balanced nutrition and regular physical activity
• Early screening: For high-risk groups (e.g., smokers, occupational exposures)