A cough lasting more than 8 weeks is more than just an inconvenience—it could be a sign of a serious chronic respiratory disease. Many people ignore a persistent cough, assuming it’s a lingering cold or allergy, but it could actually point to underlying conditions like Tuberculosis (TB), Interstitial Lung Disease (ILD), asthma, chronic bronchitis, or even lung cancer.

In this blog, we’ll break down the key differences and early warning signs of TB and ILD, highlight their overlapping symptoms, and guide you on when to seek medical attention. If you or someone you know has a cough that won't go away, read on—this could be a crucial step toward early diagnosis and better lung health.

What Is a Chronic Cough?

A chronic cough is defined as a cough that persists for more than 8 weeks in adults or more than 4 weeks in children. It may be dry or produce mucus (productive), and it often disrupts sleep, work, and quality of life.

Common Causes of Chronic Cough Include:

  • Tuberculosis (TB)

  • Interstitial Lung Disease (ILD)

  • Asthma

  • Chronic Obstructive Pulmonary Disease (COPD)

  • Postnasal drip

  • Acid reflux (GERD)

  • Smoker’s cough

  • Lung cancer

Tuberculosis (TB): A Leading Cause of Chronic Cough in India

TB is a highly infectious bacterial disease that primarily affects the lungs. It remains a major public health issue in India and other developing countries.

Red Flags of Pulmonary Tuberculosis (TB):

  • Cough lasting more than 2–3 weeks, often with blood-tinged sputum

  • Unexplained weight loss

  • Night sweats and persistent low-grade fever

  • Fatigue and chest pain

  • Loss of appetite

Who’s at Risk?

  • People living in crowded or poorly ventilated areas

  • Individuals with weakened immunity (e.g., HIV patients)

  • People with malnutrition or diabetes

  • Close contact with a person diagnosed with TB

Early diagnosis and prompt treatment with anti-tubercular therapy (ATT) can cure TB and prevent complications. If ignored, it can cause lung damage and spread to others.

Interstitial Lung Disease (ILD): An Overlooked Culprit

ILD is a group of chronic, progressive lung diseases that cause scarring (fibrosis) of lung tissue. This leads to stiff lungs and difficulty in breathing.

Symptoms of ILD You Shouldn't Ignore:

  • Persistent dry cough that doesn’t improve with antibiotics

  • Progressive shortness of breath, especially during physical activity

  • Chest tightness or discomfort

  • Clubbing of fingers

  • Fatigue and unexplained weight loss

Causes and Risk Factors of ILD:

  • Autoimmune diseases (e.g., rheumatoid arthritis, lupus)

  • Environmental exposure (silica, asbestos, mold)

  • Certain medications or radiation therapy

  • Genetic predisposition

  • Post-COVID pulmonary fibrosis

ILD is often misdiagnosed as asthma or bronchitis, leading to delayed treatment. Early HRCT chest imaging and pulmonary function tests are key to diagnosis.

TB vs. ILD: How to Tell the Difference?

Feature Tuberculosis (TB) Interstitial Lung Disease (ILD)
Type of cough Productive (with or without blood) Dry, non-productive
Fever Common, especially at night Rare or low-grade
Sputum Often yellow or blood-tinged Usually absent
Weight loss & fatigue Very common Common in later stages
Imaging (X-ray/HRCT) Cavity lesions or infiltrates Diffuse fibrosis, ground-glass opacities
Treatment Anti-TB drugs (6–9 months) Steroids, antifibrotics, oxygen support

Other Chronic Respiratory Illnesses to Consider

Asthma:

  • Wheezing, cough worse at night or early morning

  • Triggers: dust, cold air, allergens

  • Reversible with inhalers and bronchodilators

Chronic Bronchitis (COPD):

  • Productive cough with daily sputum for 3+ months/year

  • Strongly linked to smoking

  • Can lead to progressive breathlessness and lung damage

Lung Cancer:

  • Persistent cough, chest pain, and coughing up blood

  • Often associated with smoking or family history

  • Needs early detection through CT scans and biopsy

When to See a Pulmonologist

If your cough lasts longer than 8 weeks and is accompanied by any of the following symptoms, consult a lung specialist (pulmonologist) immediately:

  • Coughing up blood

  • Chest pain or tightness

  • Weight loss and fatigue

  • Shortness of breath

  • Recurrent respiratory infections

  • Hoarseness or difficulty swallowing

Early diagnosis can prevent irreversible lung damage and improve quality of life.

Conclusion: Don’t Ignore That Lingering Cough

A chronic cough is never normal—it’s your body’s way of signaling that something is wrong. Whether it’s TB, ILD, asthma, or another respiratory illness, early intervention is crucial. With timely tests, proper diagnosis, and appropriate treatment, you can manage these conditions and protect your lung health.

Have a cough that just won’t go away? Help others by sharing this blog and raising awareness about chronic cough and serious lung diseases.