Osteoarthritis (OA) is the most common degenerative and painful disease of the joints in adults, and joint pain is a typical feature of the disease. Osteoarthritis is a common cause of chronic joint pain, with a prevalence of more than 30% in people over 60 years of age, and its incidence increases with age. Osteoarthritis usually affects large weight-bearing joints asymmetrically, with the knee being more frequently involved. Rheumatoid factor (RF), which is frequently examined clinically for the diagnosis of rheumatoid arthritis, lacks specificity; patients with osteoarthritis may be positive for RF, whereas patients with rheumatoid arthritis may be negative for RF, especially early in the course of the disease. Anti-inflammatory drugs are not the first choice of medication for patients with osteoarthritis because osteoarthritis is not an inflammatory disease. The most common form of chronic arthritis at the Xuanwu Hospital Pain Clinic of Capital Medical University, Ni Jiachang, is degenerative osteoarthritis. For patients with chronic joint pain, the distinction between inflammatory or degenerative arthritis is fundamental because the pathological changes, the pattern of joint involvement, and the treatment of inflammatory and degenerative arthritis are different. Keeping the supporting tissues around the joint in a good functional state is key to reducing new complaints of pain and preserving joint function. Osteoarthritis may be the result of years of overuse, but too much joint rest is detrimental to symptom improvement. Too much rest can cause more damage to the joint from small traumas because the joint lacks the normal protective mechanisms provided by strong muscles, tendons and ligaments. Epidemiology Arthritis is one of the most common chronic pain disorders, diagnosed in 8% to 16% of the population in Europe and the United States [1]. Because its prevalence increases with age, it has been hypothesized that the prevalence of arthritis will increase considerably in the next decade as European and American societies age. The 2002 Annual Population Survey Revision of the United States predicts a substantial increase in the elderly population over the next few decades [2]. Currently, older adults over the age of 60 account for 19% of the population in developed countries and 8% of the population in less developed countries. By 2050, it is estimated that the proportion of the elderly population will reach 32% in developed countries and 20% in less developed countries. In addition, today there are more older people than children in developed countries. By 2050, there will be one child for every two older adults. The most common arthritic diseases are degenerative (e.g., osteoarthritis [OA]) and inflammatory (e.g., rheumatoid arthritis) lesions. A survey of the Dutch population showed that 28% of the population has osteoarthritis, 2% of men and 5% of women have rheumatoid arthritis [3]. In the United States, 68% of people over the age of 55 years suffer from osteoarthritis and 2% of the American population over the age of 60 years is diagnosed with rheumatoid arthritis [4,5]. It is also estimated that approximately 7.1 million outpatients in the United States presented for osteoarthritis in 1997 and another 3.9 million for rheumatoid arthritis [6]. The economic impact of arthritis is significant. Patients with arthritis lose an average of 5.2 hours of productivity per week [7]. A meta-analysis of 14 studies of costs associated with rheumatoid arthritis found that the average annual cost per patient (including direct and indirect costs) was more than $11,500 [8]. Higher costs are required early in the course of arthritis, and Söderlin et al. followed arthritis patients in Sweden from onset to six months to investigate their direct and indirect financial losses [9] and found that the average cost per arthritis patient was in the range of $3362 ($4385 for rheumatoid arthritis). In the United States, similar findings showed that the average monthly direct economic loss for rheumatoid arthritis patients in the first year was $200 and indirect economic loss was $281 [10]. The average number of working days lost per month due to rheumatoid arthritis was 3.8 ± 7.7 days.2. The main objective of the assessment of arthritis to evaluate chronic arthritis is to distinguish whether the disease is a degenerative or inflammatory lesion. The difference between the two is mainly in the medical history information. Radiographs can also be used to differentiate between osteoarthritis and rheumatoid arthritis. Osteoarthritis is often characterized by the formation of bone fragments and cartilage erosion. Rheumatoid arthritis is characterized by inflammatory changes and thinning of the cartilage layer, and sometimes by bone destruction, especially during the progressive phase of the disease. Degenerative arthritis can usually be diagnosed and managed by primary care physicians (PCPs), but patients with rheumatoid arthritis are often advised to see a rheumatologist. The relatively low prevalence of rheumatoid arthritis compared to osteoarthritis means that many PCPs have relatively limited experience diagnosing and managing rheumatoid arthritis. A comparative study found that PCPs and rheumatologists had poor diagnostic agreement for both osteoarthritis and rheumatoid arthritis when determining the relative diagnostic rates of rheumatoid disease [11]. They can improve diagnostic accuracy through physician training. in a recent study, Gormley et al. developed specific criteria for distinguishing inflammatory joint disease from non-inflammatory arthritis [12]. These criteria give PCPs and nurses diagnostic guidelines in confirming the diagnosis of inflammatory joint disease. Patients diagnosed by non-rheumatologists using Box 1 criteria will also need to be seen by a rheumatologist to further determine if they have early inflammatory disease. When diagnosing inflammatory disease, a general practitioner or rheumatology nurse using these screening criteria can obtain a rate of compliance that is more consistent with that of a rheumatologist. Among the features used in this guideline, a history report of severe joint stiffness in the morning or after rest and physical examination findings of joint swelling can clearly distinguish inflammatory from noninflammatory joint disease. The American College of Rheumatology recommends that patients newly diagnosed with rheumatoid arthritis, suspected of having rheumatoid arthritis, or who have difficulty identifying whether the arthritis is inflammatory or degenerative should be seen by a rheumatologist or other physician familiar with the diagnosis and treatment of arthritis [13]. This recommendation is supported by the fact that direct management and treatment of rheumatoid arthritis by a specialist can lead to maintenance of good joint function and pain relief [14]. This is particularly important for rheumatoid arthritis early in the course of the disease, as 13% of patients with rheumatoid arthritis are initially seen with significant joint destruction, and subsequent destruction can be minimized by aggressive management of rheumatoid arthritis [15]. Rheumatoid arthritis is sometimes associated with multisystem complications – including cardiac, renal, ocular and pulmonary complications, as well as vasculitis. Rheumatologists often also take into account the assessment of the systemic status of patients with rheumatoid arthritis. In clinical work, patients with chronic joint pain are asked to complete Figure 4, which helps to clarify the chronicity of symptoms, the location of pain, and the presence of previous symptoms of degenerative or inflammatory arthritis. Some symptoms, such as arthralgia and morning stiffness, are present in both patients with osteoarthritis and rheumatoid arthritis, although morning stiffness lasts longer in patients with rheumatoid arthritis. Patients with rheumatoid arthritis who have complaints of multisystem discomfort should be evaluated by a rheumatologist.3 Diagnosis of Arthritis When a patient’s symptoms suggest arthritis, we must clarify whether these symptoms are chronic or acute episodes before considering whether the diagnosis is osteoarthritis or rheumatoid arthritis.3.1 Osteoarthritis (OA) Osteoarthritis is a non-inflammatory joint disease. Pain is usually worse with activity or weight bearing and relieved at rest. Morning stiffness is often present. Physical examination usually reveals: joint compression, osteophytes, friction sounds on movement, and limited joint motion. Inflammatory arthritis and non-arthritic diseases (e.g., synovitis) must be ruled out before a diagnosis of osteoarthritis can be made. If the diagnosis is suspicious or if the x-ray shows normal, the patient should visit a rheumatologist for a definitive diagnosis.3.2 Rheumatoid arthritis Rheumatoid arthritis is an inflammatory joint disease of symmetrical small joints. Because rheumatoid arthritis involves other organ systems in addition to the joints, a multi-organ functional assessment is also required. The severity of symptoms at the initial visit and at each subsequent visit must be documented to determine and confirm the effectiveness of disease-controlling medications. Rheumatoid factor (RF), an autoantibody, can be detected in about 60% to 80% of patients with rheumatoid arthritis [16]. However, RF has a low specificity for rheumatoid arthritis (66%) and can also show positive titers in a variety of autoimmune diseases (e.g., dry syndrome) and non-autoimmune diseases (e.g., osteoarthritis). Therefore, RF should not be used as a routine screening test for patients with arthritis, but it still has its application in patients with clinically suspected rheumatoid arthritis. It is worth noting that RF titers may be low early in the course of rheumatoid arthritis.