I went in for a routine chest X-ray and found out I have three vertebral fractures. I didn't even know I had them. How is that possible? I don't really have a high tolerance for pain.

You didn't mention your age or sex but data show that this experience is common in postmenopausal women. The most likely cause of weakened bone resulting in fractures is osteoporosis. Osteoporosis is a decrease in bone mass. It commonly occurs with aging and especially in women after menopause.

It's estimated that 10 million people in the United States have osteoporosis. More than a million fractures are caused by osteoporosis each year. Women between the ages of 65 and 84 are affected most often.

Any bone can be affected but the wrist, hip, and spine are the most commonly affected sites. Only about half of all vertebral fractures are discovered. Many are diagnosed similar to your situation: by X-ray for something else.

Vertebral fractures aren't always pain-free. They can cause very severe and disabling pain. If the bone is fragile enough, it may collapse causing spinal instability and deformity.

Scientists aren't really sure why one person has a pain free vertebral fracture and others have extreme pain. Treatment varies according to the age, general condition, and symptoms for each patient. Sometimes the fracture has already healed and the goal is to prevent future fractures.