The lungs are part of the respiratory (breathing) system and are located in the chest, inside the rib cage and above the diaphragm.
Function of Lungs:
Oxygen enters the lungs when we inhale a breath. It is distributed throughout the lungs by a system called the bronchial tree, with branches of decreasing diameter (called bronchi and bronchioles).
The bronchial tree carries air to small sacs (alveoli) deep within the lung where oxygen from air moves from the lung into the bloodstream, and carbon dioxide, a byproduct of metabolism, moves from the blood into the lung to be exhaled.
Since the air we breathe contains many components from the environment such as dust, pollens, bacteria, viruses, smoke, and harmful chemicals, the lungs maintain a system of defense against these potentially toxic invaders.
What are Lung diseases?
Lung diseases are conditions in which some function of the lung is adversely affected. Common lung diseases include:
It is a chronic lung disease characterized by inflammation of the bronchi and bronchioles and episodes of airway obstruction.
Episodes may be triggered by cold air, exercise, cigarette smoke, or other particles in the air such as dust, mold, or allergens.
Chronic obstructive pulmonary disease (COPD)
It is a term used for both emphysema and chronic bronchitis.
With chronic bronchitis, the bronchial tubes become inflamed and scarred & With emphysema, the air sacs in the lungs are slowly destroyed.
Smoking causes about 85-90% of the deaths associated with COPD & Other risk factors include repeated exposure to air pollution.
Infections can occur primarily in the lungs, may affect the entire body, including the lungs, or may develop in the pleura, which are the membranes surrounding the lungs.
Common infections seen are,
Pneumonia: It is an acute lung tissue inflammation caused by a variety of microorganisms.
Influenza : It is an acute illness caused by a virus ( Influenza A & B , H1N1 )that includes respiratory symptoms.
Tuberculosis : It is one of very commonly encountered lung disease in clinical practise .
It is a chronic infection most commonly seen in people with weakened immune systems (such as those with HIV/AIDS) & very easily contract able.
Allergies & Lung problems
Lungs can be affected chronically & sometime with worsening condition due to allergies.
One of the common cause resulting in Ashtma
The allergies commonly are associated with exposure to environmental pollutions , house dust , pets & sometimes with food particles.
It is the uncontrolled growth of malignant cells that originate in the lungs.
According to Indian Journal of Cancer : Lung cancer is the most commonly diagnosed cancer annually since 1985. Worldwide, there are 1.61 million new cases of lung cancer per year, with 1.38 million deaths, making lung cancer the leading cause of cancer-related mortality.
In India, approximately 63,000 new lung cancer cases are reported each year.
The major risk factor for developing lung cancer is tobacco use and this disease is often viewed solely as a smoker’s disease.
What are the signs and symptoms of Lung diseases?
Signs and symptoms associated with lung disease will vary from person to person and change over time. While each disease will have its own characteristics, there are common signs and symptoms that are seen with many lung disorders, like
- Persistent cough and shortness of breath or labored breathing (dyspnea)
- Wheezing, gasping for breath
- Coughing up mucus, blood or sputum
- Chest pain
What are the Lab Tests required for screening Lung diseases?
The goals of testing are to diagnose lung diseases, determine their causes where possible, and evaluate their severity.
COMPLETE BODY PROFILE: This helps in getting an overall status of body & its functions .
- Tests for pneumonia or other specific infections:
- Bacterial sputum culture and Gram stain – to diagnose lung infections caused by bacteria or fungi
- AFB testing – to diagnose tuberculosis or a nontuberculous mycobacteria (NTM) infection
- Blood cultures – to diagnose bacteria and sometimes yeast infections that have spread into the blood
- Influenza tests – to diagnose influenza (flu) & H1N1
- Fungal tests
TEST FOR ALLERGY
Allergy tests – may be ordered to determine asthma triggers, importantly “INHALED ALLERGENS”
SCREENING FOR LUNG CANCER
- Sputum cytology – to evaluate lung cells for abnormal changes or for cancer
- Serum Biomarker analysis
OTHER TEST TO SUPPORT THE DIAGNOSIS OF LUNG DISEASES
- X-ray Chest
- Lung function tests (pulmonary function tests, PFT): Spirometry : Important investigation to evaluate “PULMONARY FUNCTIONS”
- Tests for autoantibodies may help determine if an autoimmune disorder is affecting the lungs-ANA & Anti-ds DNA