A cancer that begins in the lungs and most often occurs in people who smoke.
Lungs are two spongy organs in chest that take in oxygen when you inhale and release carbon dioxide when you exhale

Risk factors

• Smoking
  Your risk of lung cancer increases with the number of cigarettes you smoke each day and the number of years you have smoked (pack-year)
• Exposure to second-hand smoke

Symptoms

• A new cough that doesn't go away
• Coughing up blood, even a small amount
• Shortness of breath
• Chest pain
• Hoarseness
• Losing weight without trying