Every primary care doctor has been faced with this situation. A patient reports vague symptoms and is very worried that they are a sign of a catastrophic illness. The symptoms aren't even slightly suggestive of the disease the patient is worried about, but the patient’s neighbor’s brother-in-law was just diagnosed with the same disease, and so the patient is pretty sure that he has it too. The doctor is not at all suspicious that the patient has this disease. The doctor believes that the patie...