Osteoporosis (porous bones) is a progressive bone disease that is characterized by a decrease in bone density with an increased risk of fractures. Osteoporosis is defined by the World Health Organization (WHO) as a bone mineral density of 2.5 standard deviations or more below the mean peak bone mass (average of young, healthy adults) as measured by dual-energy X-ray absorptiometry. The most common form of osteoporosis occurs in women after menopause. Senile osteoporosis occurs after age 75 and is seen in both females and males at a ratio of 2:1. Secondary osteoporosis occurs at any age and affects men and women equally. Chronic predisposing medical problems or prolonged use of medications such as glucorticoids cause secondary osteoporosis. A number of medications can increase the risk of osteoporosis.