A calculus (plural calculi), often called a stone, is a concretion of material, usually mineral salts, that forms in an organ or duct of the body. Formation of calculi is known as lithiasis (/ˌlɪˈθaɪəsᵻs/). Stones can cause a number of medical conditions.
Some common principles (below) apply to stones at any location, but for specifics see the particular stone type in question.
Calculi are not to be confused with gastroliths.
Medicine (British English i/ˈmɛdsᵻn/; American English i/ˈmɛdᵻsᵻn/) is the science and practice of the diagnosis, treatment, and prevention of disease. The word medicine is derived from Latin medicus, meaning "a physician". Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness.
Contemporary medicine applies biomedical sciences, biomedical research, genetics, and medical technology to diagnose, treat, and prevent injury and disease, typically through pharmaceuticals or surgery, but also through therapies as diverse as psychotherapy, external splints and traction, medical devices, biologics, and ionizing radiation, amongst others.
Medicine has existed for thousands of years, during most of which it was an art (an area of skill and knowledge) frequently having connections to the religious and philosophical beliefs of local culture. For example, a medicine man would apply herbs and say prayers for healing, or an ancient philosopher and physician would apply bloodletting according to the theories of humorism. In recent centuries, since the advent of science, most medicine has become a combination of art and science (both basic and applied, under the umbrella of medical science). While stitching technique for sutures is an art learned through practice, the knowledge of what happens at the cellular and molecular level in the tissues being stitched arises through science.
Medicine is an open access peer-reviewed medical journal published by Lippincott Williams & Wilkins. It was established in 1922. Of general medical journals still in publication since 1959, Medicine had the highest number of citations per paper between 1959 and 2009. The journal covers all aspects of clinical medicine. On March 31, 2014 Medicine changed into an open access publication, publishing in a broad spectrum of medical specialties.
The journal is abstracted and indexed in:
This article deals with medicine as practiced by trained professionals from ancient times to the present. Early medical traditions include those of Babylon, China, Egypt and India. The Greeks went even further, introducing the concepts of medical diagnosis, prognosis, and advanced medical ethics. The Hippocratic Oath, still taken (although significantly changed from the original) by doctors up to today, was written in Greece in the 5th century BCE. In the medieval age, surgical practices inherited from the ancient masters were improved and then systematized in Rogerius's The Practice of Surgery. Universities began systematic training of physicians around the years 1220 in Italy. During the Renaissance, understanding of anatomy improved, and the microscope was invented. The germ theory of disease in the 19th century led to cures for many infectious diseases. Military doctors advanced the methods of trauma treatment and surgery. Public health measures were developed especially in the 19th century as the rapid growth of cities required systematic sanitary measures. Advanced research centers opened in the early 20th century, often connected with major hospitals. The mid-20th century was characterized by new biological treatments, such as antibiotics. These advancements, along with developments in chemistry, genetics, and lab technology (such as the x-ray) led to modern medicine. Medicine was heavily professionalized in the 20th century, and new careers opened to women as nurses (from the 1870s) and as physicians (especially after 1970). The 21st century is characterized by highly advanced research involving numerous fields of science.