If a patient has pain in the right side of the back when taking a deep breath, there are usually several factors: 1. The most common factor is respiratory disease, such as a patient with tension pneumothorax, or pleurisy, massive pneumonia, or lung infection, in which case there will be pain in the right side of the back with a deep breath. 2. In this case, there will be pain in the right side of the back with deep breathing. 3. In some cardiogenic diseases, such as unstable angina pectoris in coronary atherosclerotic heart disease, there will also be the above symptoms.