Usually starting in the lung tissue or airways (bronchi), lung cancer is the unchecked proliferation of malignant cells in the lungs. It is the world's leading cause of cancer deaths, and the main risk factor is smoking.
Two Primary Types:
NSCLC, or non-small cell lung cancer (around 85% of cases)
- Subtypes include large cell carcinoma, squamous cell carcinoma, and adenocarcinoma.
- Slows growth but is frequently diagnosed later.
SCLC (small cell lung cancer) (around 15% of cases)
- Faster spreading and more aggressive (frequently to brain, liver, and bones).
- Strongly associated with smoking.
Common Symptoms of Lung Cancer
Symptoms often appear only in advanced stages, but early signs may include:
Respiratory Symptoms:
- Persistent cough (worsening over time).
- Coughing up blood (hemoptysis).
- Shortness of breath (dyspnea).
- Wheezing or hoarseness.
- Recurrent lung infections (pneumonia, bronchitis).
Systemic Symptoms:
- Unexplained weight loss.
- Fatigue & weakness.
- Loss of appetite.
Symptoms from Cancer Spread (Metastasis):
- Bone pain (if spread to bones).
- Headaches/neurological issues (if spread to brain).
- Jaundice (if spread to liver).
- Swollen lymph nodes (neck/clavicle area).
Paraneoplastic Syndromes (Rare):
- Hypercalcemia (high calcium, causing confusion, nausea).
- Cushing syndrome (excess cortisol).
- Clubbing of fingers (due to chronic low oxygen).
When to See a Doctor?
- Persistent cough >3 weeks.
- Coughing up blood (even small amounts).
- Unexplained weight loss + fatigue.
- Smokers or ex-smokers with new respiratory symptoms.
