Body weight is not a measure of obesity. In medicine, we use body mass index to assess the degree of obesity; Body mass index (BMI) = weight (kilograms) รท height ^ 2 (meters); Adults’ BMI: 1, too light: less than 18.5; 2, normal: 18.5-24.99; 3, overweight: 25-28; 4, obesity: 28-32; 5, very obese, more than 32 Race The prevalence of osteoarthritis varies by race and by population. Epidemiologic surveys have shown that blacks are at increased risk for osteoarthritis of the knee in women compared to whites. Heredity The heritability of osteoarthritis of the knee is higher among siblings and between mothers and offspring than between fathers and offspring. Simply put, a mother with osteoarthritis of the knee has a much higher chance of developing it in her children. Occupation The high prevalence of occupational work (carpenters, painters, miners, shipbuilders, soccer players, etc.) suggests that strain on the joints can increase joint degeneration; studies have shown an increased risk of squatting or kneeling for more than 30 minutes a day, climbing more than 10 flights of stairs, and lifting more than 25 kg of weight, which is a five-fold increase in risk. Climate People who often live in damp, cold environments tend to have symptoms. This may be due to low temperature and poor blood circulation in the bone; however, there was an epidemiological survey in the northern cities of China that showed that the onset of osteoarthritis of the knee has nothing to do with the cold factor; the cold factor is known as the three evils in Chinese medicine, wind, cold and dampness, and the three evils will block the blood flow, and then the pain will be produced by the pain, resulting in a knee paralysis symptom, so osteoarthritis of the knee has the term of “Old Cold Leg” in the north; all things considered, the risk of osteoarthritis is increased. Therefore, knee osteoarthritis in the north is also known as “old cold leg”; comprehensive consideration, it is recommended that we pay attention to the warmth of the knee joint. Caused by secondary factors (trauma, inflammation, immunity, metabolism, etc.). For example, joint trauma, rheumatoid arthritis, gout, diabetes mellitus, scoliosis and other diseases can lead to osteoarthritis of the knee.