Osteoporosis is a disease that is the result of low bone density. Bones become brittle and can break very easily, even with the slightest bump. It also may cause vertebrae in the back to collapse into one another causing the spine to curve and/or shrink in length.
For more information, visit the National Library of Medicine's osteoporosis site: www.nlm.nih.gov/medlineplus/osteoporosis.html.
