Did you know that up to 90% of peak bone mass is reached by age 18 for women and age 20 for men? After your mid-30s you begin to slowly lose bone. Read more about peak bone mass.

Almost 80% of bone density is determined by heredity, and 20% by lifestyle. Bone mineral density tests (BMD) shows how dense bones are and whether you have osteoporosis. This information helps determine which prevention or treatment steps are needed. Learn more.

The most common osteoporosis test is dual X-ray absorptometry -- also called DXA or DEXA. It measures people’s spine, hip, or total body bone density to help gauge fracture risk. Read more.

Various methods can check bone density, including ultrasound and quantitative computed tomography (QCT).  Bone density scores and cost may vary by testing method.  Learn about these tests.

Bone density normally drops with age. When should you get a bone density test? Read guidelines from the National Osteoporosis Foundation.

Whether you're being screened or treated for osteoporosis, your doctor may order a blood or urine test to see the metabolism of bone. This provides clues to the progression of your disease.