The diagnosis, prognosis, prevention, treatment, palliation, and promotion of a patient's health are all aspects of patient care that fall within the purview of medicine as both a scientific discipline and a clinical practise. The term "medicine" refers to a broad category of techniques in the field of health care that have been developed through time to promote and preserve health by focusing on the avoidance and cure of disease. Modern medicine makes use of the biomedical sciences, biomedical research, genetics, and medical technology in order to diagnose, treat, and prevent illness and injury. This is typically accomplished through the use of pharmaceuticals or surgical procedures, but it can also be accomplished through treatments as varied as psychotherapy, external splints and traction, medical devices, biologics, and ionising radiation, amongst others.
Medicine has been practised ever since ancient times; throughout the most of this time period, it was considered an art (a field requiring specific skills and knowledge) and often had linkages to the religious and philosophical beliefs of the civilization in which it was practised. For instance, a medicine man might apply herbs and chant prayers for healing, or an ancient philosopher and physician would perform bloodletting according to the teachings of humorism. Both of these methods were used for the purpose of restoring health. Since the beginning of the contemporary scientific era a few centuries ago, the majority of medical practise has evolved into a hybrid of artistic and scientific principles (both basic and applied, under the umbrella of medical science). For instance, although the proper way to sew sutures is a skill that can only be mastered by repeated practise, the understanding of what occurs on a cellular and molecular level in the tissues that are being stitched is gained via scientific research.
Traditional medicine and folk medicine are the names given to prescientific traditions of medicine, which are still widely practised in spite of the existence of scientific medicine and are hence referred to as alternative medicine. Quackery refers to alternative therapies that fall outside of the realm of scientific medicine and raise questions about their effectiveness and safety.