Many people think lung cancer is caused by smoking cigarettes, but this is not the case. Smoking exponentially increases your **risk** of lung cancer (as well as cancer affecting other parts of the body), but it's not the **cause**.

Cells in the body are essentially 'programmed' to die (apoptosis). When cells do grow uncontrollably and don't die as part of their cycle, we consider them cancerous. These cells keep growing and builds up mass until a tumour is eventually formed.

There are many carcinogens that damage DNA like the sun, or car fumes that people are exposed to every day. These are much harder to avoid and thus, even without smoking, one can suffer from lung cancer.