<s>[INST] Could I really have arthritis? I'm 39! [/INST] When you think of arthritis, you picture stiff, sore seniors doing water aerobics, but the truth is, nearly 60% of people diagnosed are under age 65. Arthritis typically affects people over 40, but it can happen sooner, especially if you've had a joint injury. Being overweight may lead to arthritis of the knees because of the increased stress on the joints. Genes may also play a role: Middle-aged and older women with a family history of arthritis have a particularly high risk. But although age is a risk factor, arthritis doesn’t have to be an inevitable part of getting older. Source: Prevention. Link: https://www.prevention.com/health/a20469909/answers-to-your-arthritis-questions/. Field: Rheumatology. Disease: Arthritis </s>