Osteoporosis causes bones to become weak and brittle — so brittle that a fall or even mild stresses such as bending over or coughing can cause a fracture. Osteoporosis-related fractures most commonly occur in the hip, wrist or spine.

Bone is living tissue that is constantly being broken down and replaced. Osteoporosis occurs when the creation of new bone doesn’t keep up with the removal of old bone.

Osteoporosis affects men and women of all races. But white and Asian women — especially older women who are past menopause — are at highest risk. Medications, healthy diet and weight-bearing exercise can help prevent bone loss or strengthen already weak bones.

There typically are no symptoms in the early stages of bone loss. But once your bones have been weakened by osteoporosis, you may have signs and symptoms that include:

  • Back pain, caused by a fractured or collapsed vertebra
  • Loss of height over time
  • A stooped posture
  • A bone fracture that occurs much more easily than expected

Some risk factors for osteoporosis are out of your control, including:

  • Your sex. Women are much more likely to develop osteoporosis than are men.
  • Age. The older you get, the greater your risk of osteoporosis.
  • Race. You’re at greatest risk of osteoporosis if you’re white or of Asian descent.
  • Family history. Having a parent or sibling with osteoporosis puts you at greater risk, especially if your mother or father experienced a hip fracture.
  • Body frame size. Men and women who have small body frames tend to have a higher risk because they may have less bone mass to draw from as they age.

Osteoporosis is more common in people who have too much or too little of certain hormones in their bodies. Examples include:

  • Sex hormones. Lowered sex hormone levels tend to weaken bone. The reduction of estrogen levels in women at menopause is one of the strongest risk factors for developing osteoporosis. Men experience a gradual reduction in testosterone levels as they age. Treatments for prostate cancer that reduce testosterone levels in men and treatments for breast cancer that reduce estrogen levels in women are likely to accelerate bone loss.
  • Thyroid problems. Too much thyroid hormone can cause bone loss. This can occur if your thyroid is overactive or if you take too much thyroid hormone medication to treat an underactive thyroid.
  • Other glands. Osteoporosis has also been associated with overactive parathyroid and adrenal glands.

Osteoporosis is more likely to occur in people who have:

  • Low calcium intake. A lifelong lack of calcium plays a role in the development of osteoporosis. Low calcium intake contributes to diminished bone density, early bone loss and an increased risk of fractures.
  • Eating disorders. Severely restricting food intake and being underweight weakens bone in both men and women.
  • Gastrointestinal surgery. Surgery to reduce the size of your stomach or to remove part of the intestine limits the amount of surface area available to absorb nutrients, including calcium.