Osteoporosis (from the Greek osteo, meaning “bone,” por, meaning “passageway,” and osis, meaning “condition”) is a condition that reduces bone mass because the rate of bone resorption is quicker than the rate of bone deposition. The bones become very thin and porous and are easily broken. Osteoporosis is most common in the elderly, who may experience a greater number of broken bones as a result of the mechanical stresses of daily living and not from accidents or other trauma. Generally, osteoporosis is more severe in women, since their bones are thinner and less massive than men’s bones. In addition, estrogen helps to maintain bone mass, so the loss of estrogen in women after menopause contributes to more severe osteoporosis.