Types of Arthritis - Rheumatic Diseases - About Arthritis ...Arthritis is an umbrella term for various types of joint disease. Collectively, they are considered rheumatic diseases and related conditions.Arthritis - types of arthritis - WebMDWebMD gives basic information about the causes, symptoms, and treatments of arthritis.Types of Arthritis - Arthritis Foundation | Symptoms Treatments ...More than 100 forms of arthritis and related diseases exist affecting approximately 46 million Americans today. A complete listing follows: