Osteoporosis is generalized disease of the skeleton, characterized by low bone mineral density and disturbance of microarchitecture. Osteoporosis is a disease that appears in quite many people in Poland and there are many reasons for that. Many years ago osteoporosis was recognize as a disease of old people, but now it can reveal itself in every age and can lead to an increased susceptibility to fractures. There is a need to know how many factors can develop osteoporosis, for example genetic, environmental, dietetic or pharmacological. There are a lot of diseases, which might negatively effects bone mineral density. Osteoporosis mostly shows itself in those strictly connected with immobilization, such as stroke or spinal injury, and also in those with specific pharmacological treatment that negatively effects bone metabolism. And these disease are: epilepsy and sclerosis multiple. Osteoporosis is a big threat in many neurological diseases. It is vital to recognize diagnostic methods enabling to determine the bone metabolism, so as to prevent additional disorders. Taking into consideration a huge influence of everyday pharmacotherapy on bone metabolism, we are able to start diagnosis in an early stage and apply proper prophylactic.