I quit smoking a month ago and I'm coughing up blood, do I have lung cancer?

It is not uncommon for smokers to have an increase in coughing for several weeks after they quit. Smoking inhibits the work of the cilia in the lungs whose job it is to "sweep out" debris that in inhaled. They are damaged and/or paralyzed from the tar and other harmful chemicals in tobacco smoke. Once you quit, they work over time to rid your lungs of the accumulation of the gunk in your lungs.