I am 30 years old and a non-smoker, my mom smoked in the house as a child and as as kid I spent a lot of time w/my grandma and aunt who both smoke.

I have noticed (I have General anxiety disorder/panic disorder and managed asthma) that I will take a deep breath out of the clear blue. It's like my body does it on it's own.

I seem to have a slight problem being able to take a deep breath.

Is this a possible sign of lung cancer? I dont cough and any chest and back pain I have is more muscular due to my GAD.