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What causes bone loss?
Osteoporosis - causes; Low bone density - causes
Your Changing Bones
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. Your entire skeleton is replaced about every 10 years.
- As long as your body has a good balance of new and old bone, your bones 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 run in families and the disease is inherited. In general, white, older women are the most likely to have bone loss. This increases their risk of breaking a bone.
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 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 .
Osteoporosis
Osteoporosis is a disease in which bones become fragile and more likely to break (fracture).
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.
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For women, a drop in estrogen at the time of
menopause
is a major cause of bone loss.
Menopause
Menopause is the time in a woman's life when her periods (menstruation) stop. Most often, it is a natural, normal body change that most often occurs...
ImageRead Article Now Book Mark Article - For men, a drop in testosterone as they age can cause bone loss.
Your Lifestyle and Bone Loss
Your body needs calcium and vitamin D and enough exercise to build and keep strong bones.
Calcium and vitamin D
Your body needs calcium to keep your bones dense and strong. Low bone density can cause your bones to become brittle and fragile. These weak bones ...
Enough exercise
Osteoporosis - exercise; Low bone density - exercise; Osteopenia - exercise
Your body may not make enough new bone if:
- You do not eat enough high-calcium foods
- Your body does not absorb enough calcium from the foods you eat
- Your body removes more calcium than normal in the urine
Certain habits can affect your bones.
- Drinking alcohol. Too much alcohol can damage your bones. It can also put you at risk of falling and breaking a bone.
- Smoking. Men and women who smoke have weaker bones. Women who smoke after menopause have an even higher chance of fractures.
Younger women who do not have menstrual periods for a long time also have a higher risk of bone loss and osteoporosis.
Low body weight is linked to less bone mass and weaker bones.
Medical Disorders and Bone Loss
Many long-term (chronic) medical conditions can keep people confined to a bed or chair.
- This keeps the muscles and bones in their hips and spines from being used or bearing any weight.
- Not being able to walk or exercise may lead to bone loss and fractures.
Other medical conditions that may also lead to bone loss are:
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Rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis (RA) is a long-term disease. It leads to inflammation of the joints and surrounding tissues. It can also affect other organs....
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Chronic kidney disease
Chronic kidney disease
Chronic kidney disease is the slow loss of kidney function over time. The main job of the kidneys is to remove wastes and excess water from the body...
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Overactive parathyroid gland
Overactive parathyroid gland
Hyperparathyroidism is a disorder in which the parathyroid glands in your neck produce too much parathyroid hormone (PTH).
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Sometimes, medicines that treat certain medical conditions can cause osteoporosis. Some of these are:
- Hormone-blocking treatments for prostate cancer or breast cancer
- Some medicines that are used to treat seizures or epilepsy
- Glucocorticoid (steroid) medicines, if they are taken by mouth every day for more than 3 months, or are taken several times a year
Any treatment or condition that causes calcium or vitamin D to be poorly absorbed can also lead to weak bones. Some of these are:
- Gastric bypass (weight-loss surgery)
- Cystic fibrosis
- Other conditions that prevent the small intestine from absorbing nutrients well
People with eating disorders, such as anorexia nervosa or bulimia , are also at higher risk for osteoporosis.
Anorexia nervosa
Anorexia is an eating disorder that causes people lose more weight than is considered healthy for their age and height. People with this disorder may...
Bulimia
Bulimia is an eating disorder in which a person has regular episodes of eating a very large amount of food (bingeing) during which the person feels a...
What's Next?
Talk to your health care provider about your risk for bone loss and osteoporosis. Find out how to get the right amount of calcium and vitamin D, what exercise or lifestyle changes are right for you, and what medicines you may need to take.
Exercise or lifestyle changes
Osteoporosis - exercise; Low bone density - exercise; Osteopenia - exercise
What medicines
Alendronate (Fosamax); Ibandronate (Boniva); Risedronate (Actonel); Zoledronic acid (Reclast); Raloxifene (Evista); Teriparatide (Forteo); Denosumab ...
References
Cosman F, de Beur SJ, LeBoff MS, et al. Clinician's guide to prevention and treatment of osteoporosis. Osteoporos Int . 2014;25(10):2359-2381. PMID: 25182228 www.ncbi.nlm.nih.gov/pubmed/25182228 .
De Paula FJA, Black DM, Rosen CJ. Osteoporosis and bone biology. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: Elsevier; 2016:chap 29.
Maes C, Kronenberg HM. Bone development and remodeling. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric . 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 60.
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Osteoporosis
Animation
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Vitamin D benefit - illustration
Vitamin D promotes retention and absorption of calcium and phosphorus, primarily in the bones. Too much vitamin D may have the opposite effect of taking calcium from the bones and depositing it in the heart or lungs, reducing their function.
Vitamin D benefit
illustration
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Calcium source - illustration
Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has lactose intolerance or another reason, such as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the heart and circulatory system, as well as the secretion of essential hormones. There are many ways to supplement calcium, including a growing number of fortified foods.
Calcium source
illustration
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Vitamin D benefit - illustration
Vitamin D promotes retention and absorption of calcium and phosphorus, primarily in the bones. Too much vitamin D may have the opposite effect of taking calcium from the bones and depositing it in the heart or lungs, reducing their function.
Vitamin D benefit
illustration
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Calcium source - illustration
Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has lactose intolerance or another reason, such as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the heart and circulatory system, as well as the secretion of essential hormones. There are many ways to supplement calcium, including a growing number of fortified foods.
Calcium source
illustration
Review Date: 5/2/2016
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
