Smoking and Lung Cancer

Smoking lowers an individual's life expectancy as it damages the heart and lungs and other organs.Studies show a correlation between smoking and some diseases.Deaths from lung cancer in the UK correlate with the number of cigarettes smoked per year.The data alone shows a correlation but there needs to be a clear causal connection before it can be claimed that smoking cigarettes causes lung cancer.Lung cancer is a malignant tumour that begins in the lung.Lung cancer is caused by genetic damage to the DNA of cells in the airways, often caused by cigarette smoking or inhaling damaging chemicals.Damaged airway cells gain the ability to multiply unchecked, causing the growth of a tumour. Without treatment, tumours spread throughout the lung, damaging lung function.Eventually lung tumours metastasise, spreading to other parts of the body.