Rheumatic diseases are a group of disorders that primarily affect the joints, muscles, and connective tissues. They can cause pain, swelling, and stiffness, often leading to reduced mobility. Common examples include rheumatoid arthritis, osteoarthritis, and lupus. These conditions can be chronic, meaning they last for a long time and may require ongoing management. The exact cause of rheumatic diseases is often unknown, but they can involve autoimmune responses, where the body's immune system mistakenly attacks its own tissues. Treatment typically includes medications, physical therapy, and lifestyle changes to help manage symptoms and improve quality of life.