<unk>  is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in defined population. It is a cornerstone of public health, and shapes policy decisions and evidence-based practice by identifying risk factors for disease and targets for preventive healthcare.<unk> sts help with study design, collection, and statistical analysis of data, amend interpretation and dissemination of results (including peer review and occasional systematic review).<unk>  has helped develop methodology used in clinical research, public health studies, and, to a lesser extent, basic research in the biological sciences. Major areas of<unk> cal study include disease causation, transmission, outbreak investigation, disease surveillance, environmental<unk> , forensic<unk> , occupational<unk> , screening, biomonitoring, and comparisons of treatment effects such as in clinical trials.<unk> sts rely on other scientific disciplines like biology to better understand disease processes, statistics to make efficient use of the data and draw appropriate conclusions, social sciences to better understand proximate and distal causes, and engineering for exposure assessment.<unk> , literally meaning "the study of what is upon the people", is derived , suggesting that it applies only to human populations. However, the term is widely used in studies of zoological populations (veterinary<unk> , although the term "epizoology" is available, and it has also been applied to studies of plant populations (botanical or plant disease<unk> . The distinction between "epidemic" and "endemic" was first drawn by Hippocrates, to distinguish between diseases that are "visited upon" a population (epidemic) from those that "reside within" a population (endemic). The term<unk> " appears to have first been used to describe the study of epidemics in 1802 by the Spanish physician Villalba in<unk> a Española.<unk> sts also study the interaction of diseases in a population, a condition known as a syndemic. The term<unk>  is now widely applied to cover the description and causation of not only epidemic, infectious disease, but of disease in general, including related conditions. Some examples of topics examined through<unk>  include as high blood pressure, mental illness and obesity. Therefore, this<unk>  is based upon how the pattern of the disease causes change in the function of human beings.
Epidemiology
Spatial epidemiology
Clinical epidemiology
Neuroepidemiology
Environmental epidemiology
Subgroup analysis
Computational epidemiology
Epidemiological method