An internist or paediatrician who has acquired further training in the diagnosis (detection) and treatment of disorders affecting the muscles, bones, joints, ligaments, and tendons is known as a rheumatologist. These diseases can cause joint abnormalities as well as pain, edoema, and stiffness. Rheumatism is a term that has been used to describe these issues in the past. As a result, a "rheumatologist" is a doctor who specialises in the treatment of rheumatism. A group of disorders known as "systemic autoimmune diseases" is also treated by rheumatologists. "Collagen vascular illnesses" and "connective tissue diseases" are two other terms you may hear or read that indicate the same thing as systemic autoimmune disorders. This is a range of disorders in which the body's immune system attacks itself. This causes inflammation in parts of the body where it isn't needed, resulting in issues including pain, edoema, and organ damage. These disorders can damage the eyes, skin, nerves, kidneys, lungs, heart, and other internal organs, among other things. Inflammation of the joints, also known as arthritis, can be caused by any of the systemic autoimmune illnesses. As a result, rheumatologists are regarded as experts in the treatment of this category of diseases.