The immune system of a patient repeatedly attacks the joints, mistaking healthy cells for invaders. This is best described as:

1. The immune system can go wrong in two distinct ways, and the question turns on separating them. 2. In the first, it mistakes the body's own healthy cells for invaders and repeatedly attacks them, which is an autoimmune disease. 3. Which part of the body suffers depends on what is targeted, and rheumatoid arthritis is the autoimmune disease that affects the joints, causing pain, stiffness and loss of function. 4. In the second failure mode the immune system breaks down and cannot do its job, which is immunosuppression, the decreased effectiveness of the immune system. 5. Immunosuppression leaves a person open to infections rather than attacking the person's own tissue, so it does not fit. 6. Psychoneuroimmunology is a research field, and a psychophysiological disorder of the respiratory system means asthma or allergy, so neither describes joints under attack. _Source: OpenStax Psychology (1st ed., CC BY 4.0), Ch 14 "Stress, Lifestyle, and Health", section 14.3 Stress and Illness_