14. Serositis
This is the clinical term for the inflammation of serous membranes such as the pleura and the pericardium. The former covers the lungs, while the latter is the outer layer of the heart. In lupus patients, they experience serositis symptoms without an actual infection. Pleural effusions or pericardial effusions can compromise the normal function of the heart and the lungs. As mentioned above, these patients experience chest pain, and their symptoms improve when they sit forward. On the stethoscope, doctors can hear a distinct sound called pleural rub or pericardial rub, and pericarditis can also be detected by electrocardiography. Peritoneal serositis is also possible when the affected serous membrane is the inner lining of the abdominal cavity. In such cases, the leading symptom would be abdominal pain.