Mr. Jackson, age 65, comes to the doctor's office complaining of a sharp pain in the right side of his chest. He says his chest hurts when he breathes deeply or coughs. This is a problem, he says, because he has been coughing a lot, has difficulty drawing breath, and feels a tightness in the center of his chest. What condition or conditions might the doctor suspect? What methods of diagnosis would the doctor use, and what specific signs would the doctor look for to pinpoint the cause?