Could there be a variance in a woman's bone density in different parts of her body? Specifically, could her bone density be fine in her lower body if she has done a lot of running or other aerobic training, but if she has not done strength training for her upper body, could her upper body bone density be poor? Also, how accurate are bone density tests that scan only the heel?

Yes, there certainly can be variance in bone density at different areas of the body. In fact, you can have bone density in the normal range in one area of the body and in the osteoporotic range in another part of the body. Generally, you have a DXA scan of the hip, spine and total body. DXA is a very low-level x-ray device that measures the density of bone. DXA scans are very precise, usually with 1% variability. The heal scan test uses ultrasound and generally is a good indicator of overall bone density. If you have a heel scan done and it indicates that you have low bone density, you need to have a follow-up with the more accurate DXA scan. If you have specific concerns about your bones, you should speak to your doctor about having your bone density checked with a DXA.