I have a collapsed lung and everytime i sneeze i feel that my chest hurts?

Be re evaluated: You did not say what caused your collapsed lung. But whether it was trauma or spontaneous if you sneeze or cough or bear down it can make the collapse worse. This can cause increased pain or difficulty breathing. Follow up with your doctor to make sure the pneumothorax hasnt increased in size.

Inflammation: Air in the pleural cavity can cause irritation leading to pain on chest wall movement, like coughing or deep breathing. Treatment depends on the cause of the collapsed lung, the size of the collapse, and other symptoms.