Bone Health and Osteoporosis Beatrice C. Lupsa, MD*, Karl Insogna, MD INTRODUCTION Osteoporosis is the most common skeletal disease in humans. It is characterized by low bone mass and microarchitectural deterioration of the bone tissue, leading to decreased bone strength and increased risk of low-energy fractures, or so-called fragility fractures. Osteoporosis affects a large number of people of both sexes and all races and its prevalence increases with age. Osteoporosis is a risk factor for frac- ture just as hypertension is for stroke. The most common osteoporotic-related frac- tures are those of the vertebrae (spine), proximal femur (hip), and distal forearm (wrist). This article focuses on postmenopausal bone health and osteoporosis. It provides guidance for providers of health care to women on proper screening, identification of secondary causes, and appropriate treatment of osteoporosis. PATHOPHYSIOLOGY The skeleton is one of the largest organ systems in the body. It consists of a mineral- ized matrix with a small but highly active cellular fraction. Bone is formed by Disclosure: The authors have nothing to disclose. Department of Internal Medicine, Yale Bone Center, Yale University School of Medicine, New Haven, CT, USA * Corresponding author. 333 Cedar Street, FMP 107, P.O. Box 208020, New Haven, CT 06519. E-mail address: beatrice.lupsa@yale.edu KEYWORDS  Osteoporosis  Menopause  Fracture  Bone loss  Bone mineral density  DXA  Calcium  Vitamin D KEY POINTS  Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone tissue leading to an increased risk of fragility fractures.  Central dual-energy X-ray absorptiometry measurements are the gold standard for deter- mining bone mineral density.  A well-balanced diet containing adequate amounts of calcium and vitamin D, exercise, and smoking cessation are important to maintaining bone health as women age.  Pharmacologic agents should be recommended in patients at high risk for fracture. Endocrinol Metab Clin N Am 44 (2015) 517–530 http://dx.doi.org/10.1016/j.ecl.2015.05.002 endo.theclinics.com 0889-8529/15/$ – see front matter Ó 2015 Elsevier Inc. All rights reserved.