Why Your Pack Years Matter
First thing’s first: what are your “pack years?” Pack years are a way of calculating lung cancer risk based on how many years a person has smoked. Here’s how the equation works:
N – number of packs a day (equivalent: 20 cigarettes) x T (total years smoked) = pack years
For example:
Edith smoked 1 pack of cigarettes daily for 20 years.