Osteopenia: when you have weak bones, but not osteoporosis. Treatment for low bone density depends on how strong your bones are--not the name of the disease.
D015502:Absorptiometry, Photon; D000368:Aged; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D012737:Sex Factors