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What is osteoporosis?

Osteoporosis ("porous bone") is a disease that weakens bones, putting them at greater risk for sudden and unexpected fractures. Osteoporosis results in an increased loss of bone mass and strength. The disease often develops without any symptoms or pain, and it is usually not discovered until the weakened bones cause painful fractures. Most of these are fractures of the hip, wrist, and spine.

Although osteoporosis occurs in both men and women, women are four times more likely to develop the disease than men. After age 50, one in two white women, and one in four white men, will have an osteoporosis-related fracture in their lifetimes. Another 30 percent have low bone density that puts them at risk of developing osteoporosis (including African-Americans).

Osteoporosis is responsible for more than 2 million fractures each year, and this number continues to grow. There are steps you can take to prevent osteoporosis from ever occurring. Treatments can also slow the rate of bone loss if you do have osteoporosis.

Who is at risk for developing osteoporosis?

There are many risk factors that increase your chance of developing osteoporosis:

  • Gender: Women over the age of 50 or postmenopausal women have the greatest risk of developing osteoporosis. Women undergo rapid bone loss in the first 10 years after entering menopause, because menopause slows the production of estrogen, a hormone that protects against excessive bone loss.
  • Age: Your risk for osteoporosis fractures increases as you age.
  • Race: Caucasian and Asian women are more likely to develop osteoporosis. However, African-American and Hispanic women are still at risk. In fact, African-American women are more likely than white women to die after a hip fracture.
  • Bone structure and body weigh: Petite and thin people have a greater risk of developing osteoporosis because they have less bone to lose than people with more body weight and larger frames.
  • Family history: If your parents or grandparents have had any signs of osteoporosis, such as a fractured hip after a minor fall, you may have a greater risk of developing the disease.
  • Nutrition: You are more likely to develop osteoporosis if your body doesn’t have enough calcium and vitamin D.
  • Lifestyle: People who lead sedentary (inactive) lifestyles have a higher risk of osteoporosis.
  • Medications: Certain medications cause side effects that may damage bone and lead to osteoporosis. These include steroids, treatments for breast cancer, and medications for treating seizures.
  • Smoking: Smoking increases the risk of fractures.
  • Alcohol use: Having one to two drinks a day (or more) increases the risk of osteoporosis.
  • Medical conditions: People who have had the following should consider earlier screening for osteoporosis (this is not a complete list):
    • Overactive thyroid, parathyroid, or adrenal glands
    • History of bariatric (weight loss) surgery
    • Hormone treatment for breast or prostate cancer
    • Eating disorders (bulimia, anorexia)
    • Organ transplant
    • Celiac disease
    • Inflammatory bowel disease
    • Missed periods
    • Blood diseases such as multiple myeloma

What causes osteoporosis?

Though the exact cause of osteoporosis is unknown, we do understand how the disease develops. Your bones are made of living, growing tissue. The inside of healthy bone looks like a sponge; this area is called trabecular bone. An outer shell of dense bone wraps around the trabecular, or spongy bone. This hard shell is called cortical bone. When osteoporosis occurs, the "holes" in the "sponge" grow larger and more numerous, which weakens the inside of the bone.

In addition to supporting the body and protecting vital organs, bones store calcium and other minerals. When the body needs calcium, it breaks down and rebuilds bone. This process, called "bone remodeling," supplies the body with needed calcium while keeping the bones strong.

Up until about age 30, a person normally builds more bone than he or she loses. After age 35, bone breakdown occurs faster than bone buildup, which causes a gradual loss of bone mass. A person who has osteoporosis loses bone mass at a greater rate. After menopause, the rate of bone breakdown occurs even more quickly.