With so many possible contributing factors, it is hard to say for sure why exactly you are having arthritic problems in many different joints. A history of trauma like a vehicle accident can definately be a contributing factor. Poor ergonomics in the work place can lead to arthritis in the neck and shoulders. High-heeled shoes can lead to severe arthritis in the feet and toes. Poor nutrition, genetics, and poor health in general can all contribute to joint deterioration.
My advice to start working on the things you can change like work place ergonomics, shoe wear, diet, and overall health. See a doctor to rule-out other factors that are changeable or manageable. And just keep swimming because that is all anyone can do as time marches on.
Dr. Christina Lasich, MD