<p>Arthritis isn't a one-note story or even a few variations on a single theme; it actually consists of more than 100 different conditions. These can be anything from relatively mild forms of tendonitis (as in 'tennis elbow') and bursitis to crippling systemic forms, such as rheumatoid arthritis. There are pain syndromes like fibromyalgia and arthritis-related disorders, such as systemic lupus erythematosus, that involve every part of the body.</p>
