How Does Smoking Cause Lung Cancer?
Introduction
According to the National Cancer Institute, smoking currently causes 87 percent of lung cancer deaths. Even those who do not smoke directly, but inhale secondhand smoke, are affected by lung cancer. In fact, approximately 3,000 lung cancer deaths caused by secondhand smoke each year.
Chemicals
Smoking not only involves the ingestion of tobacco, but also a host of other toxic poisons. Over the years at least 43 to 60 different carcinogens have been found in cigarettes, according to the American Cancer Society. A carcinogen is any ingredient that has the potential to cause cancer. These ingredients include polonium, cyanide, arsenic, methoprene, benzene and carbon monoxide.
Damage
When cigarette smoke is inhaled, the tissue cells of the lungs are exposed to the host of carcinogens contained in the smoke. Carcinogens have the unique potential to damage and change the DNA of cells in the body. The DNA is responsible for a host of functions including how fast the cells reproduce and grow.
Growth
Once a cell has been exposed to carcinogens for an extended period of time, and the DNA has been affected and the cell can become cancerous. A cancerous cell is defined as any cell in the body whose DNA has been reprogrammed to grow at an accelerated and unstoppable rate. As the affected cells continue to grow, they cause the formation of blood vessels to supply the cells with the needed nutrients to continue growing. These cells grow into masses called tumors. Eventually these tumors grow to such a size that they begin to crowd out other cells in the lungs. The added mass of the tumor makes it difficult to breathe, which decreases the amount of oxygen being sent throughout the body. Eventually the tumor can become so large that the lungs can no longer function. If a small amount of the tumor manages to break off and enter the bloodstream, or lymph system, the cancer can metastasize (spread) to other parts of the body. Here the process continues as the cells make new homes in organ tissues, growing in organs such as the heart, liver or brain. This eventually causes these organs to no longer function as well.
Tags: lung cancer, cancer deaths, Cause Lung, Cause Lung Cancer, cells lungs, Does Smoking