What's the difference between osteopenia, osteoporosis, and osteomalasia?

Degree of bone loss: Osteopenia is a mild to moderate degree of bone loss. Osteoporosis is a severe degree of bone loss. Osteomalacia results from poorly mineralized bone and would show a low density on testing even if there was a normal amount of bone. Diagnosis of osteomalacia is made by blood tests and, if necessary, by evaluating a small amount of bone taken from the pelvis.