Medicine is the science and practice of caring for patients, managing the diagnosis, prognosis, prevention, treatment and palliation of their injury or disease, while promoting their health. Medicine encompasses a variety of health care practices which evolved to maintain and restore health through the prevention and treatment of illness and infection. Contemporary medicine applies biomedical sciences, biomedical research, genetics, and medical technology to diagnose, treat, and prevent injury and disease, typically through various pharmaceuticals or surgery, but also through therapies such as psychotherapy, external splints and traction, medical devices, biologics, and ionizing radiation, amongst others.