There are over 150 rheumatic diseases, many of which are now known to involve the immune system somehow becoming confused and attacking the body’s own cells.
Some of these diseases are:
Systemic Lupus Erythematosus
Rheumatoid Arthritis
Juvenile Rheumatoid Arthritis
Sjogren’s Syndrome
Hashimoto’s Thyroiditis
Scleroderma
Dermatomyositis
Crohn’s Disease
More is becoming known about the genetics involved in autoimmune disease. For example, people with a gene called HLA-B27 are more susceptible than those without the gene to getting the Spondylitis diseases and/or Iritis, also known as Anterior Uveitis
For some rheumatic diseases, the cause is presently totally unknown, such as for the conditions below:
Polymyalgia Rheumatica
Giant Cell Arteritis aka Temporal Arteritis