Your body needs the minerals calcium and phosphate to make and keep healthy bones.
During your life, your body continues to both reabsorb old bone and create new bone.
As long as your body has a good balance of new and old bone, your bones will stay healthy and strong.
Bone loss occurs when more old bone is reabsorbed than new bone is created.
Sometimes bone loss occurs without any known cause. Other times, bone loss and thin bones tend to run in families. In general, white women are the most likely to have bone loss.
Brittle, fragile bones can be caused by anything that:
Makes your body destroy too much bone, or
Keeps your body from making enough bone
Weak bones can fracture (break) easily, even without an obvious injury.
Aging and Bone Loss
As you age, your body may reabsorb calcium and phosphate from your bones instead of keeping these minerals in your bones. This makes your bones weaker. When this process reaches a certain stage, it is called osteoporosis.
Many times, a person will fracture a bone before they even know they have bone loss. By the time a fracture occurs, the bone loss is serious.
Women over age 50 and men over age 70 have a higher risk of osteoporosis than younger women and men.
For women, a drop in estrogen at the time of menopause is a major cause of bone loss.
For men, a drop in testosterone as they age can cause bone loss.
Lewiecki EM. In the clinic. Osteoporosis. Ann Intern Med. 2011 Jul 5;155(1):ITC1-1-15; quiz ITC1-16.
National Osteoporosis Foundation. Clinician's Guide to Prevention and Treatment of Osteoporosis. Washington,DC: National Osteoporosis Foundation;2010.
Miller KK, et al. Determinants of skeletal loss and recovery in anorexia nervosa. J Clin Endocrinol Metab. 2006;91(8):2931-2937.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc