Article révisé par les pairs
Résumé : The different types of osteopenia are reviewed: osteoporesis and osteomalacia. Among the secondary osteoporoses, 2 types are separately described: tumoral osteolysis and osteitis fibrosa. The incidence and epidemiology of symptoms and complications of osteoporosis are discussed. The evolution of bone mass throughout life is followed and methods of investigating this are described. Important patho physiological mechanisms are outlined. Symptoms and physical signs produced by osteoporosis are reported, as well as the biological findings. As far as osteomalacia is concerned, the importance of establishing the diagnosis is stressed, as well as the necessity of determining the exact etiology. Only then can adequate therapy be prescribed, which will achieve complete healing. Tumoral osteolysis, characteristic of multiple myeloma, is described. Early diagnosis is necessary, since therapeutic efforts will often be successful in alleviating the symptoms. The importance of making the differential diagnosis, when confronted with osteopenia, is emphasized.