Under the current diagnostic criteria for primary osteoporosis, patients are diagnosed as having osteopenia if their bone density is between 70 and 80% of the average bone density of young adult women. Osteopenia is essentially a precursor for osteoporosis, and because prevention is the basis of osteoporosis treatment, halting the progression of osteopenia into osteoporosis is very important. In other words, the risk factors associated with osteoporosis in each patient must be assessed, and if rapid bone mass loss is expected or confirmed, drug therapy should then be actively administered.