This is a break of one or more of your vertebrae, the small bones in your spine. If you have osteoporosis, sometimes just the simple act of bending over, coughing, or lifting something heavy may cause it.
If your compression fracture is minor and develops over a long time, you may not have any symptoms. If that's the case, it may heal on its own. You might not learn about it unless you have an X-ray of the area for other reasons.