Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly throughout your life. During childhood and your teens, your body adds new bone faster than it removes old bone. After about age 20, you can lose bone faster than you make bone. To have strong bones when you are young, and to prevent bone loss when you are older, you need to get enough calcium, vitamin D, and exercise. You should also avoid smoking and drinking too much alcohol.
Bone diseases can make bones easy to break. Different kinds of bone problems include
Low bone density and osteoporosis, which make your bones weak and more likely to break
Osteogenesis imperfecta makes your bones brittle
Paget's disease of bone makes them weak
Bones can also develop cancer and infections
Other bone diseases, which are caused by poor nutrition, genetics, or problems with the rate of bone growth or rebuilding
NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases
