  arthritis (from greek arthro-, joint + -itis, inflammation; plural: arthritides) is a form of joint disorder that involves inflammation of one or more joints.thefreedictionary.com > arthritis in turn citing: *the american heritage dictionary of the english language, fourth edition copyright 2000 *the american heritage science dictionary copyright 2005arthritis. collinsdictionary.com. collins english dictionary&nbsp;â complete & unabridged 11th edition. retrieved november 24, 2012. there are over 100 different forms of arthritis.healthlineweb md the most common form, osteoarthritis (degenerative joint disease), is a result of trauma to the joint, infection of the joint, or age. other arthritis forms are rheumatoid arthritis, psoriatic arthritis, and related autoimmune diseases. septic arthritis is caused by joint infection. the major complaint by individuals who have arthritis is joint pain. pain is often a constant and may be localized to the joint affected. the pain from arthritis is due to inflammation that occurs around the joint, damage to the joint from disease, daily wear and tear of joint, muscle strains caused by forceful movements against stiff painful joints and fatigue. ==classification== there are several diseases where joint pain is primary, and is considered the main feature. generally when a person has "arthritis" it means that they have one of these diseases, which include: * osteoarthritis * rheumatoid arthritis * gout and pseudo-gout * septic arthritis * ankylosing spondylitis * juvenile idiopathic arthritis * still's disease joint pain can also be a symptom of other diseases. in this case, the arthritis is considered to be secondary to the main disease; these include: * psoriasis (psoriatic arthritis) * reactive arthritis * ehlers-danlos syndrome * haemochromatosis * hepatitis * lyme disease * sjogren's disease * hashimoto's thyroiditis * inflammatory bowel disease (including crohn's disease and ulcerative colitis) * henoch-schÃ¶nlein purpura * hyperimmunoglobulinemia d with recurrent fever * 
Aging-associated_diseases Arthritis Inflammations Rheumatology Skeletal_disorders