[Primary and secondary osteoporosis. The important role of internal medicine in its differential diagnosis].

Bone metabolism as an important part of internal medicine is covered by endocrinologists, rheumatologists and nephrologists. Primary osteoporosis is an inheritable metabolic bone disease, which can be strongly modified by lifestyle, ageing and underlying diseases. Chronic inflammatory diseases, disorders of metabolism and nutritional deficits enhance the risk. Secondary osteoporosis is caused by endocrinological disorders and drugs such as glucocorticoids. It is the task of internists to clinically recognise and diagnose prominent individual risk factors for primary osteoporosis and underlying diseases for secondary osteoporosis. The key competence of internal medicine in metabolism, hormone-related disorders, malignant diseases and in handling complex medical treatment modalities represents an indispensable segment of an interdisciplinary network approach in patient care, research and teaching. This network includes orthopaedic surgery, paediatrics and gynaecology in addition to other specialties.