Arthritis is the swelling and tenderness of one or more joints. Its main symptoms are joint pain and stiffness.
Osteoarthritis is the most common form of arthritis. It occurs when the cartilage that lines your joints is worn down or damaged and your bones rub together when you use that joint.
Rickets is a condition that affects bone development in children. It's defined by the softening and weakening of bones, usually because of an extreme and prolonged vitamin D deficiency.
Fibrous dysplasia is a benign (noncancerous) bone condition in which abnormal fibrous tissue develops in place of normal bone. Pictured is fibrous dysplasia of the right zygomatic bone.
Osteopetrosis is a bone disease that makes bone tissue abnormally compact and dense and also prone to breakage and to skeletal abnormalities.
If you have diabetes, you're at increased risk of various bone and joint disorders, among many other medical conditions brought on when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces.
As its name suggests, bone cancer begins in the bones. This is what's known as primary bone cancer, which actually is rare.