Arthritis is a blanket term that describes joint pain or joint disease. Most types of arthritis, including osteoarthritis (wear-and-tear arthritis), are more common in middle-aged and older adults. But arthritis can affect anyone of any age, including young adults. Some types of arthritis are more common in older people, but many young people in their teens, 20s, and 30s can have the condition. Symptoms of an arthritis condition are similar regardless of age, but young people tend to be affected differently than middle age and older adults.